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<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><meta name="viewport" content="width=device-width, initial-scale=0.8"/><title>8.7&nbsp;Building New Contract Combinators</title><link rel="stylesheet" type="text/css" href="../scribble.css" title="default"/><link rel="stylesheet" type="text/css" href="extras.css" title="default"/><link rel="stylesheet" type="text/css" href="../racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-style.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../doc-site.css" title="default"/><script type="text/javascript" src="../scribble-common.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../doc-site.js"></script><script type="text/javascript" src="../local-redirect/local-redirect.js"></script><script type="text/javascript" src="../local-redirect/local-user-redirect.js"></script><!--[if IE 6]><style type="text/css">.SIEHidden { overflow: hidden; }</style><![endif]--></head><body id="doc-racket-lang-org"><div class="tocset"><div class="tocview"><div class="tocviewlist tocviewlisttopspace"><div class="tocviewtitle"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,&quot;tocview_0&quot;);">&#9658;</a></td><td></td><td><a href="index.html" class="tocviewlink" data-pltdoc="x">The Racket Reference</a></td></tr></table></div><div class="tocviewsublisttop" style="display: none;" id="tocview_0"><table cellspacing="0" cellpadding="0"><tr><td align="right">1&nbsp;</td><td><a href="model.html" class="tocviewlink" data-pltdoc="x">Language Model</a></td></tr><tr><td align="right">2&nbsp;</td><td><a href="notation.html" class="tocviewlink" data-pltdoc="x">Notation for Documentation</a></td></tr><tr><td align="right">3&nbsp;</td><td><a href="syntax.html" class="tocviewlink" data-pltdoc="x">Syntactic Forms</a></td></tr><tr><td align="right">4&nbsp;</td><td><a href="data.html" class="tocviewlink" data-pltdoc="x">Datatypes</a></td></tr><tr><td align="right">5&nbsp;</td><td><a href="structures.html" class="tocviewlink" data-pltdoc="x">Structures</a></td></tr><tr><td align="right">6&nbsp;</td><td><a href="mzlib_class.html" class="tocviewlink" data-pltdoc="x">Classes and Objects</a></td></tr><tr><td align="right">7&nbsp;</td><td><a href="mzlib_unit.html" class="tocviewlink" data-pltdoc="x">Units</a></td></tr><tr><td align="right">8&nbsp;</td><td><a href="contracts.html" class="tocviewselflink" data-pltdoc="x">Contracts</a></td></tr><tr><td align="right">9&nbsp;</td><td><a href="match.html" class="tocviewlink" data-pltdoc="x">Pattern Matching</a></td></tr><tr><td align="right">10&nbsp;</td><td><a href="control.html" class="tocviewlink" data-pltdoc="x">Control Flow</a></td></tr><tr><td align="right">11&nbsp;</td><td><a href="concurrency.html" class="tocviewlink" data-pltdoc="x">Concurrency and Parallelism</a></td></tr><tr><td align="right">12&nbsp;</td><td><a href="Macros.html" class="tocviewlink" data-pltdoc="x">Macros</a></td></tr><tr><td align="right">13&nbsp;</td><td><a href="input-and-output.html" class="tocviewlink" data-pltdoc="x">Input and Output</a></td></tr><tr><td align="right">14&nbsp;</td><td><a href="security.html" class="tocviewlink" data-pltdoc="x">Reflection and Security</a></td></tr><tr><td align="right">15&nbsp;</td><td><a href="os.html" class="tocviewlink" data-pltdoc="x">Operating System</a></td></tr><tr><td align="right">16&nbsp;</td><td><a href="memory.html" class="tocviewlink" data-pltdoc="x">Memory Management</a></td></tr><tr><td align="right">17&nbsp;</td><td><a href="unsafe.html" class="tocviewlink" data-pltdoc="x">Unsafe Operations</a></td></tr><tr><td align="right">18&nbsp;</td><td><a href="running.html" class="tocviewlink" data-pltdoc="x">Running Racket</a></td></tr><tr><td align="right"></td><td><a href="doc-bibliography.html" class="tocviewlink" data-pltdoc="x">Bibliography</a></td></tr><tr><td align="right"></td><td><a href="doc-index.html" class="tocviewlink" data-pltdoc="x">Index</a></td></tr></table></div></div><div class="tocviewlist"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,&quot;tocview_1&quot;);">&#9660;</a></td><td>8&nbsp;</td><td><a href="contracts.html" class="tocviewlink" data-pltdoc="x">Contracts</a></td></tr></table><div class="tocviewsublist" style="display: block;" id="tocview_1"><table cellspacing="0" cellpadding="0"><tr><td align="right">8.1&nbsp;</td><td><a href="data-structure-contracts.html" class="tocviewlink" data-pltdoc="x">Data-<wbr></wbr>structure Contracts</a></td></tr><tr><td align="right">8.2&nbsp;</td><td><a href="function-contracts.html" class="tocviewlink" data-pltdoc="x">Function Contracts</a></td></tr><tr><td align="right">8.3&nbsp;</td><td><a href="parametric-contracts.html" class="tocviewlink" data-pltdoc="x">Parametric Contracts</a></td></tr><tr><td align="right">8.4&nbsp;</td><td><a href="Lazy_Data-structure_Contracts.html" class="tocviewlink" data-pltdoc="x">Lazy Data-<wbr></wbr>structure Contracts</a></td></tr><tr><td align="right">8.5&nbsp;</td><td><a href="Structure_Type_Property_Contracts.html" class="tocviewlink" data-pltdoc="x">Structure Type Property Contracts</a></td></tr><tr><td align="right">8.6&nbsp;</td><td><a href="attaching-contracts-to-values.html" class="tocviewlink" data-pltdoc="x">Attaching Contracts to Values</a></td></tr><tr><td align="right">8.7&nbsp;</td><td><a href="" class="tocviewselflink" data-pltdoc="x">Building New Contract Combinators</a></td></tr><tr><td align="right">8.8&nbsp;</td><td><a href="contract-utilities.html" class="tocviewlink" data-pltdoc="x">Contract Utilities</a></td></tr><tr><td align="right">8.9&nbsp;</td><td><a href="racket_contract_base.html" class="tocviewlink" data-pltdoc="x"><span class="RktModLink"><span class="RktSym">racket/<span class="mywbr"> &nbsp;</span>contract/<span class="mywbr"> &nbsp;</span>base</span></span></a></td></tr><tr><td align="right">8.10&nbsp;</td><td><a href="collapsible.html" class="tocviewlink" data-pltdoc="x">Collapsible Contracts</a></td></tr><tr><td align="right">8.11&nbsp;</td><td><a href="Legacy_Contracts.html" class="tocviewlink" data-pltdoc="x">Legacy Contracts</a></td></tr><tr><td align="right">8.12&nbsp;</td><td><a href="Random_generation.html" class="tocviewlink" data-pltdoc="x">Random generation</a></td></tr></table></div></div><div class="tocviewlist"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,&quot;tocview_2&quot;);">&#9658;</a></td><td>8.7&nbsp;</td><td><a href="" class="tocviewselflink" data-pltdoc="x">Building New Contract Combinators</a></td></tr></table><div class="tocviewsublistbottom" style="display: none;" id="tocview_2"><table cellspacing="0" cellpadding="0"><tr><td align="right">8.7.1&nbsp;</td><td><a href="#%28part._.Blame_.Objects%29" class="tocviewlink" data-pltdoc="x">Blame Objects</a></td></tr><tr><td align="right">8.7.2&nbsp;</td><td><a href="#%28part._.Contracts_as_structs%29" class="tocviewlink" data-pltdoc="x">Contracts as structs</a></td></tr><tr><td align="right">8.7.3&nbsp;</td><td><a href="#%28part._.Obligation_.Information_in_.Check_.Syntax%29" class="tocviewlink" data-pltdoc="x">Obligation Information in Check Syntax</a></td></tr><tr><td align="right">8.7.4&nbsp;</td><td><a href="#%28part._.Utilities_for_.Building_.New_.Combinators%29" class="tocviewlink" data-pltdoc="x">Utilities for Building New Combinators</a></td></tr></table></div></div></div><div class="tocsub"><div class="tocsubtitle">On this page:</div><table class="tocsublist" cellspacing="0"><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._make-contract%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">make-<wbr></wbr>contract</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._make-chaperone-contract%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">make-<wbr></wbr>chaperone-<wbr></wbr>contract</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._make-flat-contract%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">make-<wbr></wbr>flat-<wbr></wbr>contract</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._build-compound-type-name%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">build-<wbr></wbr>compound-<wbr></wbr>type-<wbr></wbr>name</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contract%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">coerce-<wbr></wbr>contract</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contracts%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">coerce-<wbr></wbr>contracts</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-chaperone-contract%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">coerce-<wbr></wbr>chaperone-<wbr></wbr>contract</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-chaperone-contracts%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">coerce-<wbr></wbr>chaperone-<wbr></wbr>contracts</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-flat-contract%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">coerce-<wbr></wbr>flat-<wbr></wbr>contract</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-flat-contracts%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">coerce-<wbr></wbr>flat-<wbr></wbr>contracts</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contract%2Ff%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">coerce-<wbr></wbr>contract/<span class="mywbr"> &nbsp;</span>f</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._get%2Fbuild-val-first-projection%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">get/<span class="mywbr"> &nbsp;</span>build-<wbr></wbr>val-<wbr></wbr>first-<wbr></wbr>projection</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._get%2Fbuild-late-neg-projection%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">get/<span class="mywbr"> &nbsp;</span>build-<wbr></wbr>late-<wbr></wbr>neg-<wbr></wbr>projection</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._skip-projection-wrapper~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">skip-<wbr></wbr>projection-<wbr></wbr>wrapper?</span></span></a></td></tr><tr><td><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._with-contract-continuation-mark%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktStxLink">with-<wbr></wbr>contract-<wbr></wbr>continuation-<wbr></wbr>mark</span></span></a></td></tr><tr><td><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-pos%2Fneg-doubling%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktStxLink">contract-<wbr></wbr>pos/<span class="mywbr"> &nbsp;</span>neg-<wbr></wbr>doubling</span></span></a></td></tr><tr><td><span class="tocsublinknumber">8.7.1<tt>&nbsp;</tt></span><a href="#%28part._.Blame_.Objects%29" class="tocsubseclink" data-pltdoc="x">Blame Objects</a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">raise-<wbr></wbr>blame-<wbr></wbr>error</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-add-context%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>add-<wbr></wbr>context</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-context%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>context</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-positive%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>positive</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-negative%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>negative</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-contract%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>contract</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-value%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>value</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-source%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>source</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-swap%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>swap</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-original~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>original?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-swapped~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>swapped?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-replace-negative%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>replace-<wbr></wbr>negative</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-update%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>update</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-missing-party~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>missing-<wbr></wbr>party?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-add-missing-party%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">blame-<wbr></wbr>add-<wbr></wbr>missing-<wbr></wbr>party</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._exn~3afail~3acontract~3ablame%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">exn:<span class="mywbr"> &nbsp;</span>fail:<span class="mywbr"> &nbsp;</span>contract:<span class="mywbr"> &nbsp;</span>blame</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._current-blame-format%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">current-<wbr></wbr>blame-<wbr></wbr>format</span></span></a></td></tr><tr><td><span class="tocsublinknumber">8.7.2<tt>&nbsp;</tt></span><a href="#%28part._.Contracts_as_structs%29" class="tocsubseclink" data-pltdoc="x">Contracts as structs</a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3acontract%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">prop:<span class="mywbr"> &nbsp;</span>contract</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3achaperone-contract%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">prop:<span class="mywbr"> &nbsp;</span>chaperone-<wbr></wbr>contract</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3aflat-contract%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">prop:<span class="mywbr"> &nbsp;</span>flat-<wbr></wbr>contract</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._prop~3acontracted%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">prop:<span class="mywbr"> &nbsp;</span>contracted</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._impersonator-prop~3acontracted%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">impersonator-<wbr></wbr>prop:<span class="mywbr"> &nbsp;</span>contracted</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._prop~3ablame%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">prop:<span class="mywbr"> &nbsp;</span>blame</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._impersonator-prop~3ablame%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">impersonator-<wbr></wbr>prop:<span class="mywbr"> &nbsp;</span>blame</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._build-flat-contract-property%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">build-<wbr></wbr>flat-<wbr></wbr>contract-<wbr></wbr>property</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._build-chaperone-contract-property%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">build-<wbr></wbr>chaperone-<wbr></wbr>contract-<wbr></wbr>property</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._build-contract-property%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">build-<wbr></wbr>contract-<wbr></wbr>property</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._contract-property~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">contract-<wbr></wbr>property?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._chaperone-contract-property~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">chaperone-<wbr></wbr>contract-<wbr></wbr>property?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._flat-contract-property~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">flat-<wbr></wbr>contract-<wbr></wbr>property?</span></span></a></td></tr><tr><td><span class="tocsublinknumber">8.7.3<tt>&nbsp;</tt></span><a href="#%28part._.Obligation_.Information_in_.Check_.Syntax%29" class="tocsubseclink" data-pltdoc="x">Obligation Information in Check Syntax</a></td></tr><tr><td><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._define%2Ffinal-prop%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktStxLink">define/<span class="mywbr"> &nbsp;</span>final-<wbr></wbr>prop</span></span></a></td></tr><tr><td><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._define%2Fsubexpression-pos-prop%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktStxLink">define/<span class="mywbr"> &nbsp;</span>subexpression-<wbr></wbr>pos-<wbr></wbr>prop</span></span></a></td></tr><tr><td><span class="tocsublinknumber">8.7.4<tt>&nbsp;</tt></span><a href="#%28part._.Utilities_for_.Building_.New_.Combinators%29" class="tocsubseclink" data-pltdoc="x">Utilities for Building New Combinators</a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-stronger~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">contract-<wbr></wbr>stronger?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-equivalent~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">contract-<wbr></wbr>equivalent?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-first-order-passes~3f%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">contract-<wbr></wbr>first-<wbr></wbr>order-<wbr></wbr>passes?</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-first-order%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">contract-<wbr></wbr>first-<wbr></wbr>order</span></span></a></td></tr></table></div></div><div class="maincolumn"><div class="main"><div class="navsettop"><span class="navleft"><form class="searchform"><input class="searchbox" style="color: #888;" type="text" tabindex="1" value="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, &quot;7.7&quot;, &quot;../&quot;);" onfocus="this.style.color=&quot;black&quot;; this.style.textAlign=&quot;left&quot;; if (this.value == &quot;...search manuals...&quot;) this.value=&quot;&quot;;" onblur="if (this.value.match(/^ *$/)) { this.style.color=&quot;#888&quot;; this.style.textAlign=&quot;center&quot;; this.value=&quot;...search manuals...&quot;; }"/></form>&nbsp;&nbsp;<a href="../index.html" title="up to the documentation top" data-pltdoc="x" onclick="return GotoPLTRoot(&quot;7.7&quot;);">top</a></span><span class="navright">&nbsp;&nbsp;<a href="attaching-contracts-to-values.html" title="backward to &quot;8.6 Attaching Contracts to Values&quot;" data-pltdoc="x">&larr; prev</a>&nbsp;&nbsp;<a href="contracts.html" title="up to &quot;8 Contracts&quot;" data-pltdoc="x">up</a>&nbsp;&nbsp;<a href="contract-utilities.html" title="forward to &quot;8.8 Contract Utilities&quot;" data-pltdoc="x">next &rarr;</a></span>&nbsp;</div><h4 x-source-module="(lib &quot;scribblings/reference/reference.scrbl&quot;)" x-source-pkg="racket-doc" x-part-tag="&quot;Building_New_Contract_Combinators&quot;">8.7<tt>&nbsp;</tt><a name="(part._.Building_.New_.Contract_.Combinators)"></a><a name="(mod-path._racket/contract/combinator)"></a>Building New Contract Combinators</h4><p><table cellspacing="0" cellpadding="0" class="defmodule"><tr><td align="left"><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._require%29%29" class="RktStxLink" data-pltdoc="x">require</a></span><span class="stt"> </span><a href="" class="RktModLink" data-pltdoc="x"><span class="RktSym">racket/contract/combinator</span></a><span class="RktPn">)</span></td><td align="right"><span class="RpackageSpec"><span class="Smaller">&nbsp;package:</span> <a href="https://pkgs.racket-lang.org/package/base" title="Install this package using `raco pkg install base`"><span class="stt">base</span></a></span></td></tr></table></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top" colspan="3"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/prop..rkt)._make-contract))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._make-contract%29%29" class="RktValDef RktValLink" data-pltdoc="x">make-contract</a></span></span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span>[</td><td valign="top"><span class="RktPn">#:name</span><span class="hspace">&nbsp;</span><span class="RktVar">name</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:first-order</span><span class="hspace">&nbsp;</span><span class="RktVar">test</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:collapsible-late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:val-first-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:projection</span><span class="hspace">&nbsp;</span><span class="RktVar">proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:stronger</span><span class="hspace">&nbsp;</span><span class="RktVar">stronger</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:equivalent</span><span class="hspace">&nbsp;</span><span class="RktVar">equivalent</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:list-contract?</span><span class="hspace">&nbsp;</span><span class="RktVar">is-list-contract?</span>]<span class="RktPn">)</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">name</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">anonymous-contract</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">test</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#t</span><span class="RktPn">)</span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="values.html#%28def._%28%28quote._~23~25kernel%29._values%29%29" class="RktValLink" data-pltdoc="x">values</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="collapsible.html#%28def._%28%28lib._racket%2Fcontract%2Fcollapsible..rkt%29._collapsible-contract~3f%29%29" class="RktValLink" data-pltdoc="x">collapsible-contract?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">b</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28quote._~23~25kernel%29._if%29%29" class="RktStxLink" data-pltdoc="x">if</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktVar">test</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">x</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">b</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVal">'</span><span class="RktVal">(</span><span class="RktVal">expected:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~a"</span><span class="hspace">&nbsp;</span><span class="RktVal">given:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~e"</span><span class="RktVal">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVar">name</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr></table></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">stronger</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">equivalent</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">is-list-contract?</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top" colspan="3"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/combinator..rkt)._make-chaperone-contract))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._make-chaperone-contract%29%29" class="RktValDef RktValLink" data-pltdoc="x">make-chaperone-contract</a></span></span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span>[</td><td valign="top"><span class="RktPn">#:name</span><span class="hspace">&nbsp;</span><span class="RktVar">name</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:first-order</span><span class="hspace">&nbsp;</span><span class="RktVar">test</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:collapsible-late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:val-first-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:projection</span><span class="hspace">&nbsp;</span><span class="RktVar">proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:stronger</span><span class="hspace">&nbsp;</span><span class="RktVar">stronger</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:equivalent</span><span class="hspace">&nbsp;</span><span class="RktVar">equivalent</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:list-contract?</span><span class="hspace">&nbsp;</span><span class="RktVar">is-list-contract?</span>]<span class="RktPn">)</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._chaperone-contract~3f%29%29" class="RktValLink" data-pltdoc="x">chaperone-contract?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">name</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">anonymous-chaperone-contract</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">test</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#t</span><span class="RktPn">)</span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="values.html#%28def._%28%28quote._~23~25kernel%29._values%29%29" class="RktValLink" data-pltdoc="x">values</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="collapsible.html#%28def._%28%28lib._racket%2Fcontract%2Fcollapsible..rkt%29._collapsible-contract~3f%29%29" class="RktValLink" data-pltdoc="x">collapsible-contract?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">b</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28quote._~23~25kernel%29._if%29%29" class="RktStxLink" data-pltdoc="x">if</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktVar">test</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">x</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">b</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVal">'</span><span class="RktVal">(</span><span class="RktVal">expected:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~a"</span><span class="hspace">&nbsp;</span><span class="RktVal">given:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~e"</span><span class="RktVal">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVar">name</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr></table></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">stronger</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">equivalent</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">is-list-contract?</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top" colspan="3"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/combinator..rkt)._make-flat-contract))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._make-flat-contract%29%29" class="RktValDef RktValLink" data-pltdoc="x">make-flat-contract</a></span></span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span>[</td><td valign="top"><span class="RktPn">#:name</span><span class="hspace">&nbsp;</span><span class="RktVar">name</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:first-order</span><span class="hspace">&nbsp;</span><span class="RktVar">test</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:collapsible-late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:val-first-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:projection</span><span class="hspace">&nbsp;</span><span class="RktVar">proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:stronger</span><span class="hspace">&nbsp;</span><span class="RktVar">stronger</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:equivalent</span><span class="hspace">&nbsp;</span><span class="RktVar">equivalent</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:list-contract?</span><span class="hspace">&nbsp;</span><span class="RktVar">is-list-contract?</span>]<span class="RktPn">)</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._flat-contract~3f%29%29" class="RktValLink" data-pltdoc="x">flat-contract?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">name</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">anonymous-flat-contract</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">test</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#t</span><span class="RktPn">)</span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="values.html#%28def._%28%28quote._~23~25kernel%29._values%29%29" class="RktValLink" data-pltdoc="x">values</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="collapsible.html#%28def._%28%28lib._racket%2Fcontract%2Fcollapsible..rkt%29._collapsible-contract~3f%29%29" class="RktValLink" data-pltdoc="x">collapsible-contract?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">b</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28quote._~23~25kernel%29._if%29%29" class="RktStxLink" data-pltdoc="x">if</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktVar">test</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">x</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">b</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVal">'</span><span class="RktVal">(</span><span class="RktVal">expected:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~a"</span><span class="hspace">&nbsp;</span><span class="RktVal">given:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~e"</span><span class="RktVal">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVar">name</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr></table></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">stronger</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">equivalent</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">is-list-contract?</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">These functions build simple higher-order contracts, <a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contracts</span></a>,
and <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a>, respectively.  They all take the same set of three
optional arguments: a name, a first-order predicate, and a blame-tracking projection.
For <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._make-flat-contract%29%29" class="RktValLink" data-pltdoc="x">make-flat-contract</a></span>, see also <span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._flat-contract-with-explanation%29%29" class="RktValLink" data-pltdoc="x">flat-contract-with-explanation</a></span>.</div></p><p>The <span class="RktVar">name</span> argument is any value to be rendered using <span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._display%29%29" class="RktValLink" data-pltdoc="x">display</a></span> to
describe the contract when a violation occurs.  The default name for simple
higher-order contracts is <span class="RktRes">anonymous-contract</span>, for
<a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contracts</span></a> is <span class="RktRes">anonymous-chaperone-contract</span>, and for
<a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a> is <span class="RktRes">anonymous-flat-contract</span>.</p><p>The first-order predicate <span class="RktVar">test</span> is used to determine which values
the contract applies to.  This test is used
by <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-first-order-passes~3f%29%29" class="RktValLink" data-pltdoc="x">contract-first-order-passes?</a></span>, and indirectly by <span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span>
and <span class="RktSym">from-or/c</span> to determine which higher-order contract to wrap a
value with when there are multiple higher-order contracts to choose from.
The default test accepts any value. The predicate should be influenced by
the value of <span class="RktPn">(</span><span class="RktSym">contract-first-order-okay-to-give-up?</span><span class="RktPn">)</span> (see it&rsquo;s documentation
for more explanation).</p><p>The <span class="RktVar">late-neg-proj</span> argument defines the behavior of applying
 the contract via a <a name="(tech._late._neg._projection)"></a><span style="font-style: italic">late neg projection</span>. If it is supplied, this
 argument accepts a <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a> that is missing one party (see also
 <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-missing-party~3f%29%29" class="RktValLink" data-pltdoc="x">blame-missing-party?</a></span>).  Then it must return a function that accepts
 both the value that is getting the contract and the name of the missing blame
 party, in that order. The result must either be the value (perhaps suitably
 wrapped with a <a href="chaperones.html#%28tech._chaperone%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone</span></a> or <a href="chaperones.html#%28tech._impersonator%29" class="techoutside" data-pltdoc="x"><span class="techinside">impersonator</span></a> to enforce the
 contract), or signal a contract violation using <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span>.
 The default is <span class="RktVal">#f</span>.</p><p>The <span class="RktVar">collapsible-late-neg-proj</span> argument takes the place of the
 <span class="RktVar">late-neg-proj</span> argument for contracts that support collapsing.
 If it is supplied, this argument accepts a <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a> that is
 missing one party. It must return two values. The first value must be
 a function that accepts both the value that is getting the contract and
 the name of the missing blame party, in that order. The second value should
 be a <a href="collapsible.html#%28tech._collapsible._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">collapsible</span></a> representation of the contract.</p><p>The projection <span class="RktVar">proj</span> and <span class="RktVar">val-first-proj</span> are older mechanisms for
 defining the behavior of applying the contract.  The <span class="RktVar">proj</span> argument
is a curried function of two arguments: the first application accepts a blame
object, and the second accepts a value to protect with the contract.  The
projection must either produce the value, suitably wrapped to enforce any
higher-order aspects of the contract, or signal a contract violation using
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span>.  The default projection produces an error when the
first-order test fails, and produces the value unchanged otherwise.
The <span class="RktVar">val-first-proj</span> is like <span class="RktVar">late-neg-proj</span>, except with
an extra layer of currying.</p><p>At least one of the <span class="RktVar">late-neg-proj</span>, <span class="RktVar">proj</span>,
 <span class="RktVar">val-first-proj</span>, or <span class="RktVar">test</span> must be non-<span class="RktVal">#f</span>.</p><p>The projection arguments (<span class="RktVar">late-neg-proj</span>, <span class="RktVar">proj</span>, and
 <span class="RktVar">val-first-proj</span>) must be in sync with the <span class="RktVar">test</span> argument.
 In particular, if the test argument returns <span class="RktVal">#f</span> for some value,
 then the projections must raise a blame error for that value and if the
 test argument returns <span class="RktVal">#t</span> for some value, then the projection must
 not signal any blame for this value, unless there are higher-order interactions
 later. In other words, for <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a>, the <span class="RktVar">test</span> and
 <span class="RktSym">projection</span> arguments must check the same predicate (which is
 why thee default projection uses the <span class="RktVar">test</span> argument directly).</p><p>Projections for <a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contracts</span></a> must produce a value that passes
<span class="RktSym"><a href="chaperones.html#%28def._%28%28quote._~23~25kernel%29._chaperone-of~3f%29%29" class="RktValLink" data-pltdoc="x">chaperone-of?</a></span> when compared with the original, uncontracted value.
Projections for <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a> must fail precisely when the first-order test
does, and must produce the input value unchanged otherwise.  Applying a
<a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contract</span></a> may result in either an application of the predicate, or the
projection, or both; therefore, the two must be consistent.  The existence of a
separate projection only serves to provide more specific error messages.  Most
<a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a> do not need to supply an explicit projection.</p><p>The <span class="RktVar">stronger</span> argument is used to implement <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-stronger~3f%29%29" class="RktValLink" data-pltdoc="x">contract-stronger?</a></span>. The
first argument is always the contract itself and the second argument is whatever
was passed as the second argument to <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-stronger~3f%29%29" class="RktValLink" data-pltdoc="x">contract-stronger?</a></span>. If no
<span class="RktVar">stronger</span> argument is supplied, then a default that compares its arguments
with <span class="RktSym"><a href="Equality.html#%28def._%28%28quote._~23~25kernel%29._equal~3f%29%29" class="RktValLink" data-pltdoc="x">equal?</a></span> is used for <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a> and <a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contracts</span></a>.
For <a href="contracts.html#%28tech._impersonator._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">impersonator contracts</span></a> constructed with <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._make-contract%29%29" class="RktValLink" data-pltdoc="x">make-contract</a></span> that do not
supply the <span class="RktVar">stronger</span> argument, <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-stronger~3f%29%29" class="RktValLink" data-pltdoc="x">contract-stronger?</a></span> returns <span class="RktVal">#f</span>.</p><p>Similarly, the <span class="RktVar">equivalent</span> argument is used to implement <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-equivalent~3f%29%29" class="RktValLink" data-pltdoc="x">contract-equivalent?</a></span>.
If it isn&rsquo;t supplied or <span class="RktVal">#false</span> is supplied, then <span class="RktSym"><a href="Equality.html#%28def._%28%28quote._~23~25kernel%29._equal~3f%29%29" class="RktValLink" data-pltdoc="x">equal?</a></span> is used
for chaperone and flat contracts, and <span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="stt"> </span><span class="RktPn">(</span><span class="RktSym">x</span><span class="stt"> </span><span class="RktSym">y</span><span class="RktPn">)</span><span class="stt"> </span><span class="RktVal">#f</span><span class="RktPn">)</span> is used otherwise.</p><p>The <span class="RktVar">is-list-contract?</span> argument is used by the <span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._list-contract~3f%29%29" class="RktValLink" data-pltdoc="x">list-contract?</a></span> predicate
to determine if this is a contract that accepts only <span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._list~3f%29%29" class="RktValLink" data-pltdoc="x">list?</a></span> values.</p><p><div class="SIntrapara">Examples:</div><div class="SIntrapara"><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define%29%29" class="RktStxLink" data-pltdoc="x">define</a></span><span class="hspace">&nbsp;</span><span class="RktSym">int/c</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._make-flat-contract%29%29" class="RktValLink" data-pltdoc="x">make-flat-contract</a></span><span class="hspace">&nbsp;</span><span class="RktPn">#:name</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">int/c</span><span class="hspace">&nbsp;</span><span class="RktPn">#:first-order</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="attaching-contracts-to-values.html#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fbase..rkt%29._contract%29%29" class="RktStxLink" data-pltdoc="x">contract</a></span><span class="hspace">&nbsp;</span><span class="RktSym">int/c</span><span class="hspace">&nbsp;</span><span class="RktVal">1</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">positive</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">negative</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">1</span></p></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="attaching-contracts-to-values.html#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fbase..rkt%29._contract%29%29" class="RktStxLink" data-pltdoc="x">contract</a></span><span class="hspace">&nbsp;</span><span class="RktSym">int/c</span><span class="hspace">&nbsp;</span><span class="RktVal">"not one"</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">positive</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">negative</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktErr">eval:4:0: broke its own contract</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">promised: int/c</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">produced: "not one"</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">in: int/c</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">contract from: positive</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">blaming: positive</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;</span><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">(assuming the contract is correct)</span></p></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym">int/c</span><span class="hspace">&nbsp;</span><span class="RktVal">1</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#t</span></p></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym">int/c</span><span class="hspace">&nbsp;</span><span class="RktVal">"not one"</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#f</span></p></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define%29%29" class="RktStxLink" data-pltdoc="x">define</a></span><span class="hspace">&nbsp;</span><span class="RktSym">int-&gt;int/c</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._make-contract%29%29" class="RktValLink" data-pltdoc="x">make-contract</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">#:name</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">int-&gt;int/c</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">#:first-order</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._and%29%29" class="RktStxLink" data-pltdoc="x">and</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="procedures.html#%28def._%28%28quote._~23~25kernel%29._procedure~3f%29%29" class="RktValLink" data-pltdoc="x">procedure?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="procedures.html#%28def._%28%28quote._~23~25kernel%29._procedure-arity-includes~3f%29%29" class="RktValLink" data-pltdoc="x">procedure-arity-includes?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="hspace">&nbsp;</span><span class="RktVal">1</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">#:projection</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">b</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="let.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._let%29%29" class="RktStxLink" data-pltdoc="x">let</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym">domain</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">(</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-projection%29%29" class="RktValLink" data-pltdoc="x">contract-projection</a></span><span class="hspace">&nbsp;</span><span class="RktSym">int/c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-swap%29%29" class="RktValLink" data-pltdoc="x">blame-swap</a></span><span class="hspace">&nbsp;</span><span class="RktSym">b</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">]</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">[</span><span class="RktSym"><a href="pairs.html#%28def._%28%28lib._racket%2Flist..rkt%29._range%29%29" class="RktValLink" data-pltdoc="x">range</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">(</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-projection%29%29" class="RktValLink" data-pltdoc="x">contract-projection</a></span><span class="hspace">&nbsp;</span><span class="RktSym">int/c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym">b</span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">f</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28quote._~23~25kernel%29._if%29%29" class="RktStxLink" data-pltdoc="x">if</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._and%29%29" class="RktStxLink" data-pltdoc="x">and</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="procedures.html#%28def._%28%28quote._~23~25kernel%29._procedure~3f%29%29" class="RktValLink" data-pltdoc="x">procedure?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">f</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="procedures.html#%28def._%28%28quote._~23~25kernel%29._procedure-arity-includes~3f%29%29" class="RktValLink" data-pltdoc="x">procedure-arity-includes?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">f</span><span class="hspace">&nbsp;</span><span class="RktVal">1</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="pairs.html#%28def._%28%28lib._racket%2Flist..rkt%29._range%29%29" class="RktValLink" data-pltdoc="x">range</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">domain</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">b</span><span class="hspace">&nbsp;</span><span class="RktSym">f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVal">'</span><span class="RktVal">(</span><span class="RktVal">expected</span><span class="hspace">&nbsp;</span><span class="RktVal">"a function of one argument"</span><span class="hspace">&nbsp;</span><span class="RktVal">given:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~e"</span><span class="RktVal">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">f</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="attaching-contracts-to-values.html#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fbase..rkt%29._contract%29%29" class="RktStxLink" data-pltdoc="x">contract</a></span><span class="hspace">&nbsp;</span><span class="RktSym">int-&gt;int/c</span><span class="hspace">&nbsp;</span><span class="RktVal">"not fun"</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">positive</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">negative</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktErr">eval:8:0: broke its own contract;</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;</span><span class="RktErr">promised a function of one argument</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">produced: "not fun"</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">in: int-&gt;int/c</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">contract from: positive</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">blaming: positive</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;</span><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">(assuming the contract is correct)</span></p></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define%29%29" class="RktStxLink" data-pltdoc="x">define</a></span><span class="hspace">&nbsp;</span><span class="RktSym">halve</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="attaching-contracts-to-values.html#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fbase..rkt%29._contract%29%29" class="RktStxLink" data-pltdoc="x">contract</a></span><span class="hspace">&nbsp;</span><span class="RktSym">int-&gt;int/c</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="generic-numbers.html#%28def._%28%28quote._~23~25kernel%29._%2F%29%29" class="RktValLink" data-pltdoc="x">/</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="hspace">&nbsp;</span><span class="RktVal">2</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">positive</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">negative</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym">halve</span><span class="hspace">&nbsp;</span><span class="RktVal">2</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">1</span></p></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym">halve</span><span class="hspace">&nbsp;</span><span class="RktVal">1/2</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktErr">halve: contract violation</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">expected: int/c</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">given: 1/2</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">in: int-&gt;int/c</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">contract from: positive</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">blaming: negative</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;</span><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">(assuming the contract is correct)</span></p></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym">halve</span><span class="hspace">&nbsp;</span><span class="RktVal">1</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktErr">halve: broke its own contract</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">promised: int/c</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">produced: 1/2</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">in: int-&gt;int/c</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">contract from: positive</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">blaming: positive</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;</span><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">(assuming the contract is correct)</span></p></td></tr></table></blockquote></div></p><p class="SHistory">Changed in version 6.0.1.13 of package <span class="stt">base</span>: Added the <span class="RktPn">#:list-contract?</span> argument.<br/>Changed in version 6.90.0.30: Added the <span class="RktPn">#:equivalent</span> argument.<br/>Changed in version 7.1.0.10: Added the <span class="RktPn">#:collapsible-late-neg-projection</span> argument.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._build-compound-type-name))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._build-compound-type-name%29%29" class="RktValDef RktValLink" data-pltdoc="x">build-compound-type-name</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">c/s</span><span class="hspace">&nbsp;</span><span class="RktMeta">...</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%29%29" class="RktStxLink" data-pltdoc="x">any</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">c/s</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Produces an S-expression to be used as a name
for a contract. The arguments should be either contracts or
symbols. It wraps parentheses around its arguments and
extracts the names from any contracts it is supplied with.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._coerce-contract))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contract%29%29" class="RktValDef RktValLink" data-pltdoc="x">coerce-contract</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span><span class="RktVar">v</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Converts a regular Racket value into an instance of a contract struct,
converting it according to the description of <a href="contracts.html#%28tech._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">contracts</span></a>.</div></p><p>If <span class="RktVar">v</span> is not one of the coercible values,
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contract%29%29" class="RktValLink" data-pltdoc="x">coerce-contract</a></span> signals an error, using the first argument in
the error message.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._coerce-contracts))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contracts%29%29" class="RktValDef RktValLink" data-pltdoc="x">coerce-contracts</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span><span class="RktVar">vs</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">vs</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span></td></tr></table></blockquote></div><div class="SIntrapara">Coerces all of the arguments in <span class="RktVar">vs</span> into contracts (via
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contract%2Ff%29%29" class="RktValLink" data-pltdoc="x">coerce-contract/f</a></span>) and signals an error if any of them are not
contracts.  The error messages assume that the function named by
<span class="RktVar">id</span> got <span class="RktVar">vs</span> as its entire argument list.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._coerce-chaperone-contract))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-chaperone-contract%29%29" class="RktValDef RktValLink" data-pltdoc="x">coerce-chaperone-contract</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span><span class="RktVar">v</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._chaperone-contract~3f%29%29" class="RktValLink" data-pltdoc="x">chaperone-contract?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Like <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contract%29%29" class="RktValLink" data-pltdoc="x">coerce-contract</a></span>, but requires the result
to be a <a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contract</span></a>, not an arbitrary contract.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._coerce-chaperone-contracts))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-chaperone-contracts%29%29" class="RktValDef RktValLink" data-pltdoc="x">coerce-chaperone-contracts</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span><span class="RktVar">vs</span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._chaperone-contract~3f%29%29" class="RktValLink" data-pltdoc="x">chaperone-contract?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">vs</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span></td></tr></table></blockquote></div><div class="SIntrapara">Like <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contracts%29%29" class="RktValLink" data-pltdoc="x">coerce-contracts</a></span>, but requires the results
to be <a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contracts</span></a>, not arbitrary contracts.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._coerce-flat-contract))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-flat-contract%29%29" class="RktValDef RktValLink" data-pltdoc="x">coerce-flat-contract</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span><span class="RktVar">v</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._flat-contract~3f%29%29" class="RktValLink" data-pltdoc="x">flat-contract?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Like <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contract%29%29" class="RktValLink" data-pltdoc="x">coerce-contract</a></span>, but requires the result
to be a <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contract</span></a>, not an arbitrary contract.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._coerce-flat-contracts))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-flat-contracts%29%29" class="RktValDef RktValLink" data-pltdoc="x">coerce-flat-contracts</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span><span class="RktVar">v</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._flat-contract~3f%29%29" class="RktValLink" data-pltdoc="x">flat-contract?</a></span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span></td></tr></table></blockquote></div><div class="SIntrapara">Like <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contracts%29%29" class="RktValLink" data-pltdoc="x">coerce-contracts</a></span>, but requires the results
to be <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a>, not arbitrary contracts.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._coerce-contract/f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contract%2Ff%29%29" class="RktValDef RktValLink" data-pltdoc="x">coerce-contract/f</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">v</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Like <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._coerce-contract%29%29" class="RktValLink" data-pltdoc="x">coerce-contract</a></span>, but returns <span class="RktVal">#f</span> if
the value cannot be coerced to a contract.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._get/build-val-first-projection))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._get%2Fbuild-val-first-projection%29%29" class="RktValDef RktValLink" data-pltdoc="x">get/build-val-first-projection</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">c</span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">c</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Returns the <span class="RktVar">val-first</span> projection for <span class="RktVar">c</span>.</div></p><p>See <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._make-contract%29%29" class="RktValLink" data-pltdoc="x">make-contract</a></span> for more details.</p><p class="SHistory">Added in version 6.1.1.5 of package <span class="stt">base</span>.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._get/build-late-neg-projection))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._get%2Fbuild-late-neg-projection%29%29" class="RktValDef RktValLink" data-pltdoc="x">get/build-late-neg-projection</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">c</span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">c</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Returns the <span class="RktVar">late-neg</span> projection for <span class="RktVar">c</span>.</div></p><p>If <span class="RktVar">c</span> does not have a <span class="RktVar">late-neg</span> contract,
then this function uses the original projection for it
and logs a warning to the <span class="RktVal">'</span><span class="RktVal">racket/contract</span> logger.</p><p>See <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._make-contract%29%29" class="RktValLink" data-pltdoc="x">make-contract</a></span> for more details.</p><p class="SHistory">Added in version 6.2.900.11 of package <span class="stt">base</span>.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>parameter</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/combinator..rkt)._skip-projection-wrapper~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._skip-projection-wrapper~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">skip-projection-wrapper?</a></span></span><span class="RktPn"></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="RktPn">(</span><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._skip-projection-wrapper~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">skip-projection-wrapper?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">wrap?</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="void.html#%28def._%28%28quote._~23~25kernel%29._void~3f%29%29" class="RktValLink" data-pltdoc="x">void?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">wrap?</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">The functions <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._make-chaperone-contract%29%29" class="RktValLink" data-pltdoc="x">make-chaperone-contract</a></span> and
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._build-chaperone-contract-property%29%29" class="RktValLink" data-pltdoc="x">build-chaperone-contract-property</a></span> wrap their
arguments to ensure that the result of the projections
are chaperones of the input. This layer of wrapping can,
in some cases, introduce unwanted overhead into contract
checking. If this parameter&rsquo;s value is <span class="RktVal">#t</span>
during the dynamic extent of the call to either of those
functions, the wrapping (and thus the checks) are skipped.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>syntax</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(form._((lib._racket/contract/private/guts..rkt)._with-contract-continuation-mark))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._with-contract-continuation-mark%29%29" class="RktStxDef RktStxLink" data-pltdoc="x">with-contract-continuation-mark</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">blame</span><span class="hspace">&nbsp;</span><span class="RktVar">body</span><span class="hspace">&nbsp;</span><span class="RktMeta">...</span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._with-contract-continuation-mark%29%29" class="RktStxDef RktStxLink" data-pltdoc="x">with-contract-continuation-mark</a></span><span class="hspace">&nbsp;</span><span class="RktVar">blame+neg-party</span><span class="hspace">&nbsp;</span><span class="RktVar">body</span><span class="hspace">&nbsp;</span><span class="RktMeta">...</span><span class="RktPn">)</span></td></tr></table></blockquote></div><div class="SIntrapara">Inserts a continuation mark that informs the contract profiler (see
<a href="https://download.racket-lang.org/releases/7.7/doc/local-redirect/index.html?tag=%28part._%28.%27%28lib._contract-profile%2Fscribblings%2Fcontract-profile..scrbl%29.%27._.%27top.%27%29%29&amp;version=7.7" class="Sq" data-pltdoc="x">the contract profiling documentation</a>)
that contract checking is happening.
For the costs from checking your new combinator to be included, you should wrap
any deferred, higher-order checks with this form. First-order checks are
recognized automatically and do not require this form.</div></p><p>If your combinator&rsquo;s projections operate on complete <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame objects</span></a> (i.e., no
missing blame parties), the <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a> should be the first argument to this
form. Otherwise (e.g., in the case of <span class="RktVar">late-neg</span> projections), a pair
of the <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a> and the missing party should be used instead.</p><p class="SHistory">Added in version 6.4.0.4 of package <span class="stt">base</span>.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>syntax</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(form._((lib._racket/contract/private/guts..rkt)._contract-pos/neg-doubling))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-pos%2Fneg-doubling%29%29" class="RktStxDef RktStxLink" data-pltdoc="x">contract-pos/neg-doubling</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">e1</span><span class="hspace">&nbsp;</span><span class="RktVar">e2</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Some contract combinators need to build projections for
subcontracts with both regular and <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-swap%29%29" class="RktValLink" data-pltdoc="x">blame-swap</a></span>ed
versions of the blame that they are given in order to check
both access and mutations (e.g., <span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fvector..rkt%29._vector%2Fc%29%29" class="RktValLink" data-pltdoc="x">vector/c</a></span> and
<span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fvector..rkt%29._vectorof%29%29" class="RktValLink" data-pltdoc="x">vectorof</a></span>). In the case that such combinators are
nested deeply inside each other, there is a potential for an
exponential explosion of nested projections being built.</div></p><p>To avoid that explosion, wrap each of the calls to the
blame-accepting portion of the combinator in
<span class="RktSym"><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-pos%2Fneg-doubling%29%29" class="RktStxLink" data-pltdoc="x">contract-pos/neg-doubling</a></span>. It returns three values.
The first is a boolean, indicating how to interpret the
other two results. If the boolean is <span class="RktVal">#t</span>, then the
other two results are the values of <span class="RktVar">e1</span> and
<span class="RktVar">e2</span> and we are not too deep in the nesting. If the
boolean is <span class="RktVal">#f</span>, then we have passed a threshold and
it is not safe to evaluate <span class="RktVar">e1</span> and <span class="RktVar">e2</span> yet,
as we are in danger of running into the exponential
slowdown. In that case, the last two results are thunks
that, when invoked, compute the values of <span class="RktVar">e1</span> and
<span class="RktVar">e2</span>.</p><p>As an example, <span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fvector..rkt%29._vectorof%29%29" class="RktValLink" data-pltdoc="x">vectorof</a></span> uses
<span class="RktSym"><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-pos%2Fneg-doubling%29%29" class="RktStxLink" data-pltdoc="x">contract-pos/neg-doubling</a></span> wrapping its two calls to
the blame-accepting part of the projection for its
subcontract. When it receives a <span class="RktVal">#f</span> as that first
boolean, it does not invoke the thunks right away, but waits
until the interposition procedure that it attaches to the
chaperoned vector is called. Then it invokes them (and caches
the result). This delays the construction of the projections
until they are actually needed, avoiding the exponential blowup.</p><p class="SHistory">Added in version 6.90.0.27 of package <span class="stt">base</span>.</p><h5 x-source-module="(lib &quot;scribblings/reference/reference.scrbl&quot;)" x-source-pkg="racket-doc" x-part-tag="&quot;Blame_Objects&quot;">8.7.1<tt>&nbsp;</tt><a name="(part._.Blame_.Objects)"></a>Blame Objects</h5><p>This section describes <a name="(tech._blame._object)"></a><span style="font-style: italic">blame objects</span> and operations on them.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">v</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">This predicate recognizes <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame objects</span></a>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._raise-blame-error))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValDef RktValLink" data-pltdoc="x">raise-blame-error</a></span></span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVar">b</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:missing-party</span><span class="hspace">&nbsp;</span><span class="RktVar">missing-party</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVar">v</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVar">fmt</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVar">v-fmt</span><span class="hspace">&nbsp;</span><span class="RktMeta">...</span><span class="RktPn">)</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">&rarr;</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._none%2Fc%29%29" class="RktValLink" data-pltdoc="x">none/c</a></span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">missing-party</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">fmt</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="strings.html#%28def._%28%28quote._~23~25kernel%29._string~3f%29%29" class="RktValLink" data-pltdoc="x">string?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="strings.html#%28def._%28%28quote._~23~25kernel%29._string~3f%29%29" class="RktValLink" data-pltdoc="x">string?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVal">'</span><span class="RktVal">given</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">given:</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVal">'</span><span class="RktVal">expected</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">expected:</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr></table></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v-fmt</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Signals a contract violation.  The first argument, <span class="RktVar">b</span>, records the
current blame information, including positive and negative parties, the name of
the contract, the name of the value, and the source location of the contract
application. The <span class="RktPn">#:missing-party</span> argument supplies one of the blame
parties. It should be non-<span class="RktVal">#f</span> when the <span class="RktVar">b</span> object was created
without supplying a negative party. See <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-add-missing-party%29%29" class="RktValLink" data-pltdoc="x">blame-add-missing-party</a></span> and
the description of the <span class="RktVar">late-neg-proj</span> argument of <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._make-contract%29%29" class="RktValLink" data-pltdoc="x">make-contract</a></span>.</div></p><p>The second positional argument, <span class="RktVar">v</span>, is the value that failed to
satisfy the contract.</p><p>The remaining arguments are a format string,
<span class="RktVar">fmt</span>, and its arguments, <span class="RktVar">v-fmt</span><span class="stt"> </span><span class="RktSym"><a href="stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29._......%29%29" class="RktStxLink" data-pltdoc="x">...</a></span>, specifying an error message
specific to the precise violation.</p><p>If <span class="RktVar">fmt</span> is a list, then the elements are concatenated together
(with spaces added, unless there are already spaces at the ends of the strings),
after first replacing symbols with either their string counterparts, or
replacing <span class="RktVal">'</span><span class="RktVal">given</span> with <span class="RktVal">"produced"</span> and
<span class="RktVal">'</span><span class="RktVal">expected</span> with <span class="RktVal">"promised"</span>, depending on whether or not
the <span class="RktVar">b</span> argument has been swapped or not (see <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-swap%29%29" class="RktValLink" data-pltdoc="x">blame-swap</a></span>).</p><p>If <span class="RktVar">fmt</span> contains the symbols <span class="RktVal">'</span><span class="RktVal">given:</span> or <span class="RktVal">'</span><span class="RktVal">expected:</span>,
they are replaced like <span class="RktVal">'</span><span class="RktVal">given</span> and <span class="RktVal">'</span><span class="RktVal">expected</span> are, but
the replacements are prefixed with the string <span class="RktVal">"\n<span class="hspace">&nbsp;&nbsp;</span>"</span> to conform
to the error message guidelines in <a href="exns.html#%28part._err-msg-conventions%29" data-pltdoc="x">Error Message Conventions</a>.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-add-context))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-add-context%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-add-context</a></span></span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVar">blame</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVar">context</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span>[</td><td valign="top"><span class="RktPn">#:important</span><span class="hspace">&nbsp;</span><span class="RktVar">important</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:swap?</span><span class="hspace">&nbsp;</span><span class="RktVar">swap?</span>]<span class="RktPn">)</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">&rarr;</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">blame</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">context</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="strings.html#%28def._%28%28quote._~23~25kernel%29._string~3f%29%29" class="RktValLink" data-pltdoc="x">string?</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">important</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="strings.html#%28def._%28%28quote._~23~25kernel%29._string~3f%29%29" class="RktValLink" data-pltdoc="x">string?</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">swap?</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr></table></blockquote></div><div class="SIntrapara">Adds some context information to blame error messages
  that explicates which portion of the contract failed
  (and that gets rendered by <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span>).</div></p><p>The <span class="RktVar">context</span> argument describes one layer of the
  portion of the contract, typically of the form <span class="RktVal">"the 1st argument of"</span>
  (in the case of a function contract)
  or <span class="RktVal">"a conjunct of"</span> (in the case of an <span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._and%2Fc%29%29" class="RktValLink" data-pltdoc="x">and/c</a></span> contract).</p><p><div class="SIntrapara">For example, consider this contract violation:
  </div><div class="SIntrapara"><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="attaching-contracts-to-values.html#%28form._%28%28lib._racket%2Fcontract%2Fregion..rkt%29._define%2Fcontract%29%29" class="RktStxLink" data-pltdoc="x">define/contract</a></span><span class="hspace">&nbsp;</span><span class="RktSym">f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._list%2Fc%29%29" class="RktValLink" data-pltdoc="x">list/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._list%29%29" class="RktValLink" data-pltdoc="x">list</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktPn">(</span><span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._car%29%29" class="RktValLink" data-pltdoc="x">car</a></span><span class="hspace">&nbsp;</span><span class="RktSym">f</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktErr">f: contract violation</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">expected: integer?</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">given: #f</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">in: the 1st argument of</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">the 1st element of</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">(list/c (-&gt; integer? integer?))</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">contract from: (definition f)</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">blaming: top-level</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;</span><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">(assuming the contract is correct)</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">at: eval:2.0</span></p></td></tr></table></blockquote></div><div class="SIntrapara">It shows that the portion of the contract being violated is the first
occurrence of <span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span>, because the <span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span> and
the <span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._list%2Fc%29%29" class="RktValLink" data-pltdoc="x">list/c</a></span> combinators each internally called
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-add-context%29%29" class="RktValLink" data-pltdoc="x">blame-add-context</a></span> to add the two lines following
&ldquo;in&rdquo; in the error message.</div></p><p>The <span class="RktVar">important</span> argument is used to build the beginning part
of the contract violation. The last <span class="RktVar">important</span> argument that
gets added to a <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a> is used. The <span class="RktSym"><a href="Object_and_Class_Contracts.html#%28form._%28%28lib._racket%2Fclass..rkt%29._class%2Fc%29%29" class="RktStxLink" data-pltdoc="x">class/c</a></span> contract
adds an important argument, as does the <span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span> contract (when
<span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span> knows the name of the function getting the contract).</p><p>The <span class="RktVar">swap?</span> argument has the effect of calling <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-swap%29%29" class="RktValLink" data-pltdoc="x">blame-swap</a></span>
while adding the layer of context, but without creating an extra
<a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a>.</p><p>Passing <span class="RktVal">#f</span> as the context string argument is no longer relevant.
For backwards compatibility, <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-add-context%29%29" class="RktValLink" data-pltdoc="x">blame-add-context</a></span> returns <span class="RktSym">b</span>
when <span class="RktVar">context</span> is <span class="RktVal">#f</span>.</p><p class="SHistory">Changed in version 6.90.0.29 of package <span class="stt">base</span>: The <span class="RktVar">context</span> argument being
<span class="RktVal">#f</span> is no longer relevant.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-context))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-context%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-context</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">blame</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="strings.html#%28def._%28%28quote._~23~25kernel%29._string~3f%29%29" class="RktValLink" data-pltdoc="x">string?</a></span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">blame</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Returns the context information that would be supplied in
an error message, if <span class="RktVar">blame</span> is passed to <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-positive))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-positive%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-positive</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-negative))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-negative%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-negative</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">These functions produce printable descriptions of the current positive and
negative parties of a <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-contract))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-contract%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-contract</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">This function produces a description of the contract associated with a blame
object (the result of <span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-name%29%29" class="RktValLink" data-pltdoc="x">contract-name</a></span>).</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-value))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-value%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-value</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">This function produces the name of the value to which the contract was applied,
or <span class="RktVal">#f</span> if no name was provided.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-source))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-source%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-source</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="exns.html#%28def._%28%28quote._~23~25kernel%29._srcloc~3f%29%29" class="RktValLink" data-pltdoc="x">srcloc?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">This function produces the source location associated with a contract.  If no
source location was provided, all fields of the structure will contain
<span class="RktVal">#f</span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-swap))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-swap%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-swap</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">This function swaps the positive and negative parties of a <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a>.
(See also <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-add-context%29%29" class="RktValLink" data-pltdoc="x">blame-add-context</a></span>.)</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-original~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-original~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-original?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-swapped~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-swapped~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-swapped?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">These functions report whether the current blame of a given <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a> is the
same as in the original contract invocation (possibly of a compound contract
containing the current one), or swapped, respectively.  Each is the negation of
the other; both are provided for convenience and clarity.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-replace-negative))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-replace-negative%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-replace-negative</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span><span class="RktVar">neg</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">neg</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Produces a <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span> object just like <span class="RktVar">b</span> except
           that it uses <span class="RktVar">neg</span> instead of the negative
           position <span class="RktVar">b</span> has.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-update))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-update%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-update</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span><span class="RktVar">pos</span><span class="hspace">&nbsp;</span><span class="RktVar">neg</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">pos</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">neg</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Produces a <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span> object just like <span class="RktVar">b</span> except
           that it adds <span class="RktVar">pos</span> and <span class="RktVar">neg</span> to the positive
           and negative parties of <span class="RktVar">b</span> respectively.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-missing-party~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-missing-party~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-missing-party?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Returns <span class="RktVal">#t</span> when <span class="RktVar">b</span> does not have both parties.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._blame-add-missing-party))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-add-missing-party%29%29" class="RktValDef RktValLink" data-pltdoc="x">blame-add-missing-party</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span><span class="RktVar">missing-party</span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._and%2Fc%29%29" class="RktValLink" data-pltdoc="x">and/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._not%2Fc%29%29" class="RktValLink" data-pltdoc="x">not/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-missing-party~3f%29%29" class="RktValLink" data-pltdoc="x">blame-missing-party?</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">b</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._and%2Fc%29%29" class="RktValLink" data-pltdoc="x">and/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-missing-party~3f%29%29" class="RktValLink" data-pltdoc="x">blame-missing-party?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">missing-party</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Produces a new <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a> like <span class="RktVar">b</span>, except that the missing
party is replaced with <span class="RktVar">missing-party</span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>struct</p></div></div><table cellspacing="0" cellpadding="0" class="RForeground"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="define-struct.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._struct%29%29" class="RktStxLink" data-pltdoc="x">struct</a></span></td><td><span class="hspace">&nbsp;</span></td><td><a name="(def._((lib._racket/contract/private/blame..rkt)._exn~3afail~3acontract~3ablame-object))"></a><a name="(def._((lib._racket/contract/private/blame..rkt)._make-exn~3afail~3acontract~3ablame))"></a><a name="(def._((lib._racket/contract/private/blame..rkt)._exn~3afail~3acontract~3ablame~3f))"></a><a name="(def._((lib._racket/contract/private/blame..rkt)._struct~3aexn~3afail~3acontract~3ablame))"></a><a name="(def._((lib._racket/contract/private/blame..rkt)._exn~3afail~3acontract~3ablame))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._exn~3afail~3acontract~3ablame%29%29" class="RktValDef RktValLink" data-pltdoc="x">exn:fail:contract:blame</a></span></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="exns.html#%28def._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._exn~3afail~3acontract%29%29" class="RktValLink" data-pltdoc="x">exn:fail:contract</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">object</span><span class="RktPn">)</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">#:extra-constructor-name</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._make-exn~3afail~3acontract~3ablame%29%29" class="RktValLink" data-pltdoc="x">make-exn:fail:contract:blame</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktSym">object</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">This exception is raised to signal a contract error. The <span class="RktSym">object</span>
field contains a <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a> associated with a contract violation.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>parameter</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/blame..rkt)._current-blame-format))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._current-blame-format%29%29" class="RktValDef RktValLink" data-pltdoc="x">current-blame-format</a></span></span><span class="RktPn"></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="strings.html#%28def._%28%28quote._~23~25kernel%29._string~3f%29%29" class="RktValLink" data-pltdoc="x">string?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="strings.html#%28def._%28%28quote._~23~25kernel%29._string~3f%29%29" class="RktValLink" data-pltdoc="x">string?</a></span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="RktPn">(</span><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._current-blame-format%29%29" class="RktValDef RktValLink" data-pltdoc="x">current-blame-format</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">proc</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="void.html#%28def._%28%28quote._~23~25kernel%29._void~3f%29%29" class="RktValLink" data-pltdoc="x">void?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">proc</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="strings.html#%28def._%28%28quote._~23~25kernel%29._string~3f%29%29" class="RktValLink" data-pltdoc="x">string?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="strings.html#%28def._%28%28quote._~23~25kernel%29._string~3f%29%29" class="RktValLink" data-pltdoc="x">string?</a></span><span class="RktPn">)</span></td></tr></table></blockquote></div><div class="SIntrapara">A <a href="eval-model.html#%28tech._parameter%29" class="techoutside" data-pltdoc="x"><span class="techinside">parameter</span></a> that is used when constructing a
contract violation error. Its value is procedure that
accepts three arguments:
</div><div class="SIntrapara"><ul><li><p>the <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a> for the violation,</p></li><li><p>the value that the contract applies to, and</p></li><li><p>a message indicating the kind of violation.</p></li></ul></div><div class="SIntrapara">The procedure then
returns a string that is put into the contract error
message. Note that the value is often already included in
the message that indicates the violation.</div></p><p><div class="SIntrapara">Examples:</div><div class="SIntrapara"><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define%29%29" class="RktStxLink" data-pltdoc="x">define</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">show-blame-error</span><span class="hspace">&nbsp;</span><span class="RktSym">blame</span><span class="hspace">&nbsp;</span><span class="RktSym">value</span><span class="hspace">&nbsp;</span><span class="RktSym">message</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="strings.html#%28def._%28%28quote._~23~25kernel%29._string-append%29%29" class="RktValLink" data-pltdoc="x">string-append</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktVal">"Contract Violation!\n"</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._format%29%29" class="RktValLink" data-pltdoc="x">format</a></span><span class="hspace">&nbsp;</span><span class="RktVal">"Guilty Party: ~a\n"</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-positive%29%29" class="RktValLink" data-pltdoc="x">blame-positive</a></span><span class="hspace">&nbsp;</span><span class="RktSym">blame</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._format%29%29" class="RktValLink" data-pltdoc="x">format</a></span><span class="hspace">&nbsp;</span><span class="RktVal">"Innocent Party: ~a\n"</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-negative%29%29" class="RktValLink" data-pltdoc="x">blame-negative</a></span><span class="hspace">&nbsp;</span><span class="RktSym">blame</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._format%29%29" class="RktValLink" data-pltdoc="x">format</a></span><span class="hspace">&nbsp;</span><span class="RktVal">"Contracted Value Name: ~a\n"</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-value%29%29" class="RktValLink" data-pltdoc="x">blame-value</a></span><span class="hspace">&nbsp;</span><span class="RktSym">blame</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._format%29%29" class="RktValLink" data-pltdoc="x">format</a></span><span class="hspace">&nbsp;</span><span class="RktVal">"Contract Location: ~s\n"</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-source%29%29" class="RktValLink" data-pltdoc="x">blame-source</a></span><span class="hspace">&nbsp;</span><span class="RktSym">blame</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._format%29%29" class="RktValLink" data-pltdoc="x">format</a></span><span class="hspace">&nbsp;</span><span class="RktVal">"Contract Name: ~a\n"</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-contract%29%29" class="RktValLink" data-pltdoc="x">blame-contract</a></span><span class="hspace">&nbsp;</span><span class="RktSym">blame</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._format%29%29" class="RktValLink" data-pltdoc="x">format</a></span><span class="hspace">&nbsp;</span><span class="RktVal">"Offending Value: ~s\n"</span><span class="hspace">&nbsp;</span><span class="RktSym">value</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._format%29%29" class="RktValLink" data-pltdoc="x">format</a></span><span class="hspace">&nbsp;</span><span class="RktVal">"Offense: ~a\n"</span><span class="hspace">&nbsp;</span><span class="RktSym">message</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._current-blame-format%29%29" class="RktValLink" data-pltdoc="x">current-blame-format</a></span><span class="hspace">&nbsp;</span><span class="RktSym">show-blame-error</span><span class="RktPn">)</span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="attaching-contracts-to-values.html#%28form._%28%28lib._racket%2Fcontract%2Fregion..rkt%29._define%2Fcontract%29%29" class="RktStxLink" data-pltdoc="x">define/contract</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">f</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="generic-numbers.html#%28def._%28%28quote._~23~25kernel%29._%2F%29%29" class="RktValLink" data-pltdoc="x">/</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="hspace">&nbsp;</span><span class="RktVal">2</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym">f</span><span class="hspace">&nbsp;</span><span class="RktVal">2</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">1</span></p></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym">f</span><span class="hspace">&nbsp;</span><span class="RktVal">1</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktErr">Contract Violation!</span></p></td></tr><tr><td><p><span class="RktErr">Guilty Party: (function f)</span></p></td></tr><tr><td><p><span class="RktErr">Innocent Party: top-level</span></p></td></tr><tr><td><p><span class="RktErr">Contracted Value Name: f</span></p></td></tr><tr><td><p><span class="RktErr">Contract Location: #(struct:srcloc eval 4 0 4 1)</span></p></td></tr><tr><td><p><span class="RktErr">Contract Name: (-&gt; integer? integer?)</span></p></td></tr><tr><td><p><span class="RktErr">Offending Value: 1/2</span></p></td></tr><tr><td><p><span class="RktErr">Offense: promised: integer?</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">produced: 1/2</span></p></td></tr><tr><td><blockquote class="SubFlow"></blockquote></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym">f</span><span class="hspace">&nbsp;</span><span class="RktVal">1/2</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktErr">Contract Violation!</span></p></td></tr><tr><td><p><span class="RktErr">Guilty Party: top-level</span></p></td></tr><tr><td><p><span class="RktErr">Innocent Party: (function f)</span></p></td></tr><tr><td><p><span class="RktErr">Contracted Value Name: f</span></p></td></tr><tr><td><p><span class="RktErr">Contract Location: #(struct:srcloc eval 4 0 4 1)</span></p></td></tr><tr><td><p><span class="RktErr">Contract Name: (-&gt; integer? integer?)</span></p></td></tr><tr><td><p><span class="RktErr">Offending Value: 1/2</span></p></td></tr><tr><td><p><span class="RktErr">Offense: expected: integer?</span></p></td></tr><tr><td><p><span class="RktErr"></span><span class="hspace">&nbsp;&nbsp;</span><span class="RktErr">given: 1/2</span></p></td></tr><tr><td><blockquote class="SubFlow"></blockquote></td></tr></table></blockquote></div></p><h5 x-source-module="(lib &quot;scribblings/reference/reference.scrbl&quot;)" x-source-pkg="racket-doc" x-part-tag="&quot;Contracts_as_structs&quot;">8.7.2<tt>&nbsp;</tt><a name="(part._.Contracts_as_structs)"></a>Contracts as structs</h5><p>The property <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3acontract%29%29" class="RktValLink" data-pltdoc="x">prop:contract</a></span> allows arbitrary structures to act as
contracts.  The property <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3achaperone-contract%29%29" class="RktValLink" data-pltdoc="x">prop:chaperone-contract</a></span> allows arbitrary
structures to act as <a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contracts</span></a>; <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3achaperone-contract%29%29" class="RktValLink" data-pltdoc="x">prop:chaperone-contract</a></span>
inherits <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3acontract%29%29" class="RktValLink" data-pltdoc="x">prop:contract</a></span>, so <a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contract</span></a> structures may also act
as general contracts.  The property <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3aflat-contract%29%29" class="RktValLink" data-pltdoc="x">prop:flat-contract</a></span> allows arbitrary structures
to act as <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a>; <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3aflat-contract%29%29" class="RktValLink" data-pltdoc="x">prop:flat-contract</a></span> inherits both
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3achaperone-contract%29%29" class="RktValLink" data-pltdoc="x">prop:chaperone-contract</a></span> and <span class="RktSym"><a href="procedures.html#%28def._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._prop~3aprocedure%29%29" class="RktValLink" data-pltdoc="x">prop:procedure</a></span>, so <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contract</span></a> structures
may also act as <a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contracts</span></a>, as general contracts, and as predicate procedures.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._racket/contract/private/prop..rkt)._prop~3acontract))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3acontract%29%29" class="RktValDef RktValLink" data-pltdoc="x">prop:contract</a></span></span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="structprops.html#%28def._%28%28quote._~23~25kernel%29._struct-type-property~3f%29%29" class="RktValLink" data-pltdoc="x">struct-type-property?</a></span></p></blockquote></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._racket/contract/private/prop..rkt)._prop~3achaperone-contract))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3achaperone-contract%29%29" class="RktValDef RktValLink" data-pltdoc="x">prop:chaperone-contract</a></span></span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="structprops.html#%28def._%28%28quote._~23~25kernel%29._struct-type-property~3f%29%29" class="RktValLink" data-pltdoc="x">struct-type-property?</a></span></p></blockquote></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._racket/contract/private/prop..rkt)._prop~3aflat-contract))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3aflat-contract%29%29" class="RktValDef RktValLink" data-pltdoc="x">prop:flat-contract</a></span></span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="structprops.html#%28def._%28%28quote._~23~25kernel%29._struct-type-property~3f%29%29" class="RktValLink" data-pltdoc="x">struct-type-property?</a></span></p></blockquote></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">These properties declare structures to be contracts or <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a>,
respectively.  The value for <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3acontract%29%29" class="RktValLink" data-pltdoc="x">prop:contract</a></span> must be a <a href="#%28tech._contract._property%29" class="techoutside" data-pltdoc="x"><span class="techinside">contract
property</span></a> constructed by <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._build-contract-property%29%29" class="RktValLink" data-pltdoc="x">build-contract-property</a></span>; likewise, the value
for <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3achaperone-contract%29%29" class="RktValLink" data-pltdoc="x">prop:chaperone-contract</a></span> must be a <a href="#%28tech._chaperone._contract._property%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contract property</span></a>
constructed by <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._build-chaperone-contract-property%29%29" class="RktValLink" data-pltdoc="x">build-chaperone-contract-property</a></span> and the value
for <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3aflat-contract%29%29" class="RktValLink" data-pltdoc="x">prop:flat-contract</a></span> must be a <a href="#%28tech._flat._contract._property%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contract property</span></a>
constructed by <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._build-flat-contract-property%29%29" class="RktValLink" data-pltdoc="x">build-flat-contract-property</a></span>.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._racket/contract/private/guts..rkt)._prop~3acontracted))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._prop~3acontracted%29%29" class="RktValDef RktValLink" data-pltdoc="x">prop:contracted</a></span></span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="structprops.html#%28def._%28%28quote._~23~25kernel%29._struct-type-property~3f%29%29" class="RktValLink" data-pltdoc="x">struct-type-property?</a></span></p></blockquote></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._racket/contract/private/guts..rkt)._impersonator-prop~3acontracted))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._impersonator-prop~3acontracted%29%29" class="RktValDef RktValLink" data-pltdoc="x">impersonator-prop:contracted</a></span></span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="chaperones.html#%28def._%28%28quote._~23~25kernel%29._impersonator-property~3f%29%29" class="RktValLink" data-pltdoc="x">impersonator-property?</a></span></p></blockquote></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">These properties attach a contract value to the protected structure,
chaperone, or impersonator value.  The function <span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._has-contract~3f%29%29" class="RktValLink" data-pltdoc="x">has-contract?</a></span>
returns <span class="RktVal">#t</span> for values that have one of these properties, and
<span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._value-contract%29%29" class="RktValLink" data-pltdoc="x">value-contract</a></span> extracts the value from the property (which
is expected to be the contract on the value).</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._racket/contract/private/guts..rkt)._prop~3ablame))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._prop~3ablame%29%29" class="RktValDef RktValLink" data-pltdoc="x">prop:blame</a></span></span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="structprops.html#%28def._%28%28quote._~23~25kernel%29._struct-type-property~3f%29%29" class="RktValLink" data-pltdoc="x">struct-type-property?</a></span></p></blockquote></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._racket/contract/private/guts..rkt)._impersonator-prop~3ablame))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._impersonator-prop~3ablame%29%29" class="RktValDef RktValLink" data-pltdoc="x">impersonator-prop:blame</a></span></span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="chaperones.html#%28def._%28%28quote._~23~25kernel%29._impersonator-property~3f%29%29" class="RktValLink" data-pltdoc="x">impersonator-property?</a></span></p></blockquote></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">These properties attach a blame information to the protected structure,
chaperone, or impersonator value.  The function <span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._has-blame~3f%29%29" class="RktValLink" data-pltdoc="x">has-blame?</a></span>
returns <span class="RktVal">#t</span> for values that have one of these properties, and
<span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._value-blame%29%29" class="RktValLink" data-pltdoc="x">value-blame</a></span> extracts the value from the property.</div></p><p>The value is expected to be the blame record for the contract on the value or
a <span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._cons%29%29" class="RktValLink" data-pltdoc="x">cons</a></span>-pair of a blame record with a missing party and the missing
party. The <span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._value-blame%29%29" class="RktValLink" data-pltdoc="x">value-blame</a></span> function reassembles the arguments of the pair
into a complete blame record using <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame-add-missing-party%29%29" class="RktValLink" data-pltdoc="x">blame-add-missing-party</a></span>. If
the value has one of the properties, but the value is not a <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a>
or a pair whose <span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._car%29%29" class="RktValLink" data-pltdoc="x">car</a></span> position is a <a href="#%28tech._blame._object%29" class="techoutside" data-pltdoc="x"><span class="techinside">blame object</span></a>, then <span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._has-blame~3f%29%29" class="RktValLink" data-pltdoc="x">has-blame?</a></span>
returns <span class="RktVal">#f</span> but <span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._value-blame%29%29" class="RktValLink" data-pltdoc="x">value-blame</a></span> returns <span class="RktVal">#f</span>.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top" colspan="3"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/combinator..rkt)._build-flat-contract-property))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._build-flat-contract-property%29%29" class="RktValDef RktValLink" data-pltdoc="x">build-flat-contract-property</a></span></span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span>[</td><td valign="top"><span class="RktPn">#:name</span><span class="hspace">&nbsp;</span><span class="RktVar">get-name</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:first-order</span><span class="hspace">&nbsp;</span><span class="RktVar">get-first-order</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:collapsible-late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:val-first-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:projection</span><span class="hspace">&nbsp;</span><span class="RktVar">get-projection</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:stronger</span><span class="hspace">&nbsp;</span><span class="RktVar">stronger</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:equivalent</span><span class="hspace">&nbsp;</span><span class="RktVar">equivalent</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:generate</span><span class="hspace">&nbsp;</span><span class="RktVar">generate</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:list-contract?</span><span class="hspace">&nbsp;</span><span class="RktVar">is-list-contract?</span>]<span class="RktPn">)</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._flat-contract-property~3f%29%29" class="RktValLink" data-pltdoc="x">flat-contract-property?</a></span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">get-name</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">anonymous-flat-contract</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">get-first-order</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#t</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="values.html#%28def._%28%28quote._~23~25kernel%29._values%29%29" class="RktValLink" data-pltdoc="x">values</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="collapsible.html#%28def._%28%28lib._racket%2Fcontract%2Fcollapsible..rkt%29._collapsible-contract~3f%29%29" class="RktValLink" data-pltdoc="x">collapsible-contract?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">get-projection</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">b</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28quote._~23~25kernel%29._if%29%29" class="RktStxLink" data-pltdoc="x">if</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">(</span><span class="RktVar">get-first-order</span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">x</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">b</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">(</span><span class="RktVal">expected:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~a"</span><span class="hspace">&nbsp;</span><span class="RktVal">given:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~e"</span><span class="RktVal">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktVar">get-name</span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr></table></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">stronger</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">equivalent</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">generate</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3ei%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span>i</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym">c</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">[</span><span class="RktSym">generator</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._and%2Fc%29%29" class="RktValLink" data-pltdoc="x">and/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._positive~3f%29%29" class="RktValLink" data-pltdoc="x">positive?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._real~3f%29%29" class="RktValLink" data-pltdoc="x">real?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="Random_generation.html#%28def._%28%28lib._racket%2Fcontract..rkt%29._contract-random-generate-fail~3f%29%29" class="RktValLink" data-pltdoc="x">contract-random-generate-fail?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">fuel</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">is-list-contract?</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top" colspan="3"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/combinator..rkt)._build-chaperone-contract-property))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._build-chaperone-contract-property%29%29" class="RktValDef RktValLink" data-pltdoc="x">build-chaperone-contract-property</a></span></span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span>[</td><td valign="top"><span class="RktPn">#:name</span><span class="hspace">&nbsp;</span><span class="RktVar">get-name</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:first-order</span><span class="hspace">&nbsp;</span><span class="RktVar">get-first-order</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:collapsible-late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:val-first-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:projection</span><span class="hspace">&nbsp;</span><span class="RktVar">get-projection</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:stronger</span><span class="hspace">&nbsp;</span><span class="RktVar">stronger</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:equivalent</span><span class="hspace">&nbsp;</span><span class="RktVar">equivalent</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:generate</span><span class="hspace">&nbsp;</span><span class="RktVar">generate</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:exercise</span><span class="hspace">&nbsp;</span><span class="RktVar">exercise</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:list-contract?</span><span class="hspace">&nbsp;</span><span class="RktVar">is-list-contract?</span>]<span class="RktPn">)</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._chaperone-contract-property~3f%29%29" class="RktValLink" data-pltdoc="x">chaperone-contract-property?</a></span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">get-name</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">anonymous-chaperone-contract</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">get-first-order</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#t</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="values.html#%28def._%28%28quote._~23~25kernel%29._values%29%29" class="RktValLink" data-pltdoc="x">values</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="collapsible.html#%28def._%28%28lib._racket%2Fcontract%2Fcollapsible..rkt%29._collapsible-contract~3f%29%29" class="RktValLink" data-pltdoc="x">collapsible-contract?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">get-projection</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">b</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28quote._~23~25kernel%29._if%29%29" class="RktStxLink" data-pltdoc="x">if</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">(</span><span class="RktVar">get-first-order</span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">x</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">b</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">(</span><span class="RktVal">expected:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~a"</span><span class="hspace">&nbsp;</span><span class="RktVal">given:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~e"</span><span class="RktVal">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktVar">get-name</span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr></table></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">stronger</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">equivalent</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">generate</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3ei%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span>i</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym">c</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">[</span><span class="RktSym">generator</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._and%2Fc%29%29" class="RktValLink" data-pltdoc="x">and/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._positive~3f%29%29" class="RktValLink" data-pltdoc="x">positive?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._real~3f%29%29" class="RktValLink" data-pltdoc="x">real?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="Random_generation.html#%28def._%28%28lib._racket%2Fcontract..rkt%29._contract-random-generate-fail~3f%29%29" class="RktValLink" data-pltdoc="x">contract-random-generate-fail?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">fuel</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">exercise</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3ei%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span>i</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym">c</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">[</span><span class="RktSym">result</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._and%2Fc%29%29" class="RktValLink" data-pltdoc="x">and/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._positive~3f%29%29" class="RktValLink" data-pltdoc="x">positive?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._real~3f%29%29" class="RktValLink" data-pltdoc="x">real?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="values.html#%28def._%28%28quote._~23~25kernel%29._values%29%29" class="RktValLink" data-pltdoc="x">values</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="void.html#%28def._%28%28quote._~23~25kernel%29._void~3f%29%29" class="RktValLink" data-pltdoc="x">void?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">fuel</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="values.html#%28def._%28%28quote._~23~25kernel%29._values%29%29" class="RktValLink" data-pltdoc="x">values</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="void.html#%28def._%28%28quote._~23~25kernel%29._void%29%29" class="RktValLink" data-pltdoc="x">void</a></span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">(</span><span class="RktVal">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">is-list-contract?</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top" colspan="3"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/prop..rkt)._build-contract-property))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._build-contract-property%29%29" class="RktValDef RktValLink" data-pltdoc="x">build-contract-property</a></span></span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span>[</td><td valign="top"><span class="RktPn">#:name</span><span class="hspace">&nbsp;</span><span class="RktVar">get-name</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:first-order</span><span class="hspace">&nbsp;</span><span class="RktVar">get-first-order</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:collapsible-late-neg-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:val-first-projection</span><span class="hspace">&nbsp;</span><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:projection</span><span class="hspace">&nbsp;</span><span class="RktVar">get-projection</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:stronger</span><span class="hspace">&nbsp;</span><span class="RktVar">stronger</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:equivalent</span><span class="hspace">&nbsp;</span><span class="RktVar">equivalent</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:generate</span><span class="hspace">&nbsp;</span><span class="RktVar">generate</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:exercise</span><span class="hspace">&nbsp;</span><span class="RktVar">exercise</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">#:list-contract?</span><span class="hspace">&nbsp;</span><span class="RktVar">is-list-contract?</span>]<span class="RktPn">)</span></td><td valign="top"><span class="hspace">&nbsp;</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._contract-property~3f%29%29" class="RktValLink" data-pltdoc="x">contract-property?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">get-name</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">anonymous-contract</span><span class="RktPn">)</span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">get-first-order</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#t</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">collapsible-late-neg-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="values.html#%28def._%28%28quote._~23~25kernel%29._values%29%29" class="RktValLink" data-pltdoc="x">values</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="collapsible.html#%28def._%28%28lib._racket%2Fcontract%2Fcollapsible..rkt%29._collapsible-contract~3f%29%29" class="RktValLink" data-pltdoc="x">collapsible-contract?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">val-first-proj</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktVal">#f</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">get-projection</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._blame~3f%29%29" class="RktValLink" data-pltdoc="x">blame?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">b</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28quote._~23~25kernel%29._if%29%29" class="RktStxLink" data-pltdoc="x">if</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">(</span><span class="RktVar">get-first-order</span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">x</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fblame..rkt%29._raise-blame-error%29%29" class="RktValLink" data-pltdoc="x">raise-blame-error</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktSym">b</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">(</span><span class="RktVal">expected:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~a"</span><span class="hspace">&nbsp;</span><span class="RktVal">given:</span><span class="hspace">&nbsp;</span><span class="RktVal">"~e"</span><span class="RktVal">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktVar">get-name</span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr></table></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">stronger</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">equivalent</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktVal">#f</span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">generate</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3ei%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span>i</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym">c</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">[</span><span class="RktSym">generator</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._and%2Fc%29%29" class="RktValLink" data-pltdoc="x">and/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._positive~3f%29%29" class="RktValLink" data-pltdoc="x">positive?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._real~3f%29%29" class="RktValLink" data-pltdoc="x">real?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="Random_generation.html#%28def._%28%28lib._racket%2Fcontract..rkt%29._contract-random-generate-fail~3f%29%29" class="RktValLink" data-pltdoc="x">contract-random-generate-fail?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">fuel</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace">&nbsp;&nbsp;</span></td><td valign="top"><span class="RktVar">exercise</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">:</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3ei%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span>i</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym">c</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">[</span><span class="RktSym">result</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._and%2Fc%29%29" class="RktValLink" data-pltdoc="x">and/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._positive~3f%29%29" class="RktValLink" data-pltdoc="x">positive?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._real~3f%29%29" class="RktValLink" data-pltdoc="x">real?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="values.html#%28def._%28%28quote._~23~25kernel%29._values%29%29" class="RktValLink" data-pltdoc="x">values</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym">c</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="void.html#%28def._%28%28quote._~23~25kernel%29._void~3f%29%29" class="RktValLink" data-pltdoc="x">void?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top">=</td><td valign="top"><span class="hspace">&nbsp;</span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">fuel</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="values.html#%28def._%28%28quote._~23~25kernel%29._values%29%29" class="RktValLink" data-pltdoc="x">values</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="void.html#%28def._%28%28quote._~23~25kernel%29._void%29%29" class="RktValLink" data-pltdoc="x">void</a></span><span class="hspace">&nbsp;</span><span class="RktVal">'</span><span class="RktVal">(</span><span class="RktVal">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">is-list-contract?</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>=<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">#f</span><span class="RktPn">)</span></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">These functions build the arguments for <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3acontract%29%29" class="RktValLink" data-pltdoc="x">prop:contract</a></span>,
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3achaperone-contract%29%29" class="RktValLink" data-pltdoc="x">prop:chaperone-contract</a></span>, and <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._prop~3aflat-contract%29%29" class="RktValLink" data-pltdoc="x">prop:flat-contract</a></span>, respectively.</div></p><p><div class="SIntrapara">A <a name="(tech._contract._property)"></a><span style="font-style: italic">contract property</span> specifies the behavior of a structure when used as
a contract.  It is specified in terms of seven properties:
</div><div class="SIntrapara"><ul><li><p><span class="RktVar">get-name</span> which produces a description to <span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._write%29%29" class="RktValLink" data-pltdoc="x">write</a></span> as part
of a contract violation;</p></li><li><p><span class="RktVar">get-first-order</span>, which produces a first-order predicate to be
used by <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-first-order-passes~3f%29%29" class="RktValLink" data-pltdoc="x">contract-first-order-passes?</a></span>;</p></li><li><p><span class="RktVar">late-neg-proj</span>, which produces a blame-tracking projection
defining the behavior of the contract (The <span class="RktVar">get-projection</span>
and <span class="RktVar">val-first-proj</span> arguments also specify the projection,
but using a different signature. They are here for backwards compatibility.);</p></li><li><p><span class="RktVar">collapsible-late-neg-proj</span>, similar to <span class="RktVar">late-neg-proj</span>
which produces a blame-tracking projection defining the behavior of the
contract, this function additionally specifies the
<a href="collapsible.html#%28tech._collapsible._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">collapsible</span></a> behavior of the contract;</p></li><li><p><span class="RktVar">stronger</span>, a predicate that determines whether this
contract (passed in the first argument) is stronger than some other
contract (passed in the second argument) and whose default always
returns <span class="RktVal">#f</span>;</p></li><li><p><span class="RktVar">equivalent</span>, a predicate that determines whether this
contract (passed in the first argument) is equivalent to some other
contract (passed in the second argument); the default for flat
and chaperone contracts is <span class="RktSym"><a href="Equality.html#%28def._%28%28quote._~23~25kernel%29._equal~3f%29%29" class="RktValLink" data-pltdoc="x">equal?</a></span> and for impersonator contracts
returns <span class="RktVal">#f</span>;</p></li><li><p><span class="RktVar">generate</span>, which returns a thunk that generates random values
matching the contract (using <span class="RktSym"><a href="Random_generation.html#%28def._%28%28lib._racket%2Fcontract..rkt%29._contract-random-generate-fail%29%29" class="RktValLink" data-pltdoc="x">contract-random-generate-fail</a></span>)
to indicate failure) or <span class="RktVal">#f</span> to indicate that random
generation for this contract isn&rsquo;t supported;</p></li><li><p><span class="RktVar">exercise</span>, which returns a function that exercises values
matching the contract (e.g., if it is a function contract, it may call
the function) and a list of contracts whose values will be generated
by this process;</p></li><li><p>and <span class="RktVar">is-list-contract?</span>, which is used by <span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._flat-contract~3f%29%29" class="RktValLink" data-pltdoc="x">flat-contract?</a></span>
to determine if this contract accepts only <span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._list~3f%29%29" class="RktValLink" data-pltdoc="x">list?</a></span>s.</p></li></ul></div></p><p>At least one of the <span class="RktVar">late-neg-proj</span>, <span class="RktVar">collapsible-late-neg-proj</span>,
<span class="RktVar">get-projection</span>, <span class="RktVar">val-first-proj</span>, or <span class="RktVar">get-first-order</span>
must be non-<span class="RktVal">#f</span>.</p><p>These accessors are passed as (optional) keyword arguments to
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._build-contract-property%29%29" class="RktValLink" data-pltdoc="x">build-contract-property</a></span>, and are applied to instances of the
appropriate structure type by the contract system.  Their results are used
analogously to the arguments of <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._make-contract%29%29" class="RktValLink" data-pltdoc="x">make-contract</a></span>.</p><p>A <a name="(tech._chaperone._contract._property)"></a><span style="font-style: italic">chaperone contract property</span> specifies the behavior of a structure
when used as a chaperone contract.  It is specified using
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._build-chaperone-contract-property%29%29" class="RktValLink" data-pltdoc="x">build-chaperone-contract-property</a></span>, and accepts exactly the same set of
arguments as <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._build-contract-property%29%29" class="RktValLink" data-pltdoc="x">build-contract-property</a></span>.  The only difference is that the
projection accessor must return a value that passes <span class="RktSym"><a href="chaperones.html#%28def._%28%28quote._~23~25kernel%29._chaperone-of~3f%29%29" class="RktValLink" data-pltdoc="x">chaperone-of?</a></span> when
compared with the original, uncontracted value.</p><p><div class="SIntrapara">A <a name="(tech._flat._contract._property)"></a><span style="font-style: italic">flat contract property</span> specifies the behavior of a structure when
used as a <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contract</span></a>.  It is specified using
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._build-flat-contract-property%29%29" class="RktValLink" data-pltdoc="x">build-flat-contract-property</a></span>, and accepts similar
arguments as <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._build-contract-property%29%29" class="RktValLink" data-pltdoc="x">build-contract-property</a></span>.  The differences are:
</div><div class="SIntrapara"><ul><li><p>the projection accessor is expected not to wrap its argument in a
higher-order fashion, analogous to the constraint on projections in
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fcombinator..rkt%29._make-flat-contract%29%29" class="RktValLink" data-pltdoc="x">make-flat-contract</a></span>;</p></li><li><p>the <span class="RktPn">#:exercise</span> keyword argument is omitted because it is not
relevant for flat contracts.</p></li></ul></div></p><p class="SHistory">Changed in version 6.0.1.13 of package <span class="stt">base</span>: Added the <span class="RktPn">#:list-contract?</span> argument.<br/>Changed in version 6.1.1.4: Allow <span class="RktVar">generate</span> to return <span class="RktSym"><a href="Random_generation.html#%28def._%28%28lib._racket%2Fcontract..rkt%29._contract-random-generate-fail%29%29" class="RktValLink" data-pltdoc="x">contract-random-generate-fail</a></span>.<br/>Changed in version 6.90.0.30: Added the <span class="RktPn">#:equivalent</span> argument.<br/>Changed in version 7.1.0.10: Added the <span class="RktPn">#:collapsible-late-neg-projection</span> argument.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/prop..rkt)._contract-property~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._contract-property~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">contract-property?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">v</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/prop..rkt)._chaperone-contract-property~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._chaperone-contract-property~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">chaperone-contract-property?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">v</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="together"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/prop..rkt)._flat-contract-property~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fprop..rkt%29._flat-contract-property~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">flat-contract-property?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">v</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">These predicates detect whether a value is a <a href="#%28tech._contract._property%29" class="techoutside" data-pltdoc="x"><span class="techinside">contract property</span></a>,
<a href="#%28tech._chaperone._contract._property%29" class="techoutside" data-pltdoc="x"><span class="techinside">chaperone contract property</span></a>, or a
<a href="#%28tech._flat._contract._property%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contract property</span></a>, respectively.</div></p><h5 x-source-module="(lib &quot;scribblings/reference/reference.scrbl&quot;)" x-source-pkg="racket-doc" x-part-tag="&quot;Obligation_Information_in_Check_Syntax&quot;">8.7.3<tt>&nbsp;</tt><a name="(part._.Obligation_.Information_in_.Check_.Syntax)"></a>Obligation Information in Check Syntax</h5><p><a href="https://download.racket-lang.org/releases/7.7/doc/local-redirect/index.html?tag=%28part._%28.%27%28lib._scribblings%2Fdrracket%2Fdrracket..scrbl%29.%27._.%27buttons.%27%29%29&amp;version=7.7" class="Sq" data-pltdoc="x">Check Syntax</a> in DrRacket shows obligation information for
contracts according to <span class="RktSym"><a href="stxprops.html#%28def._%28%28quote._~23~25kernel%29._syntax-property%29%29" class="RktValLink" data-pltdoc="x">syntax-property</a></span>s that the contract combinators
leave in the expanded form of the program. These properties indicate
where contracts appear in the source and where the positive and negative
positions of the contracts appear.</p><p>To make Check Syntax show obligation information for your new contract
combinators, use the following properties (some helper macros and functions
are below):</p><ul><li><p><div class="SIntrapara"><a name="(idx._(gentag._187._(lib._scribblings/reference/reference..scrbl)))"></a>
</div><div class="SIntrapara"><span class="RktVal">'</span><span class="RktVal">racket/contract:contract</span><span class="hspace">&nbsp;</span><span class="RktSym">:</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fvector..rkt%29._vector%2Fc%29%29" class="RktValLink" data-pltdoc="x">vector/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="stxops.html#%28def._%28%28quote._~23~25kernel%29._syntax~3f%29%29" class="RktValLink" data-pltdoc="x">syntax?</a></span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="stxops.html#%28def._%28%28quote._~23~25kernel%29._syntax~3f%29%29" class="RktValLink" data-pltdoc="x">syntax?</a></span><span class="RktPn">)</span><span class="RktPn">)</span></div><div class="SIntrapara">This property should be attached to the result of a transformer
               that implements a contract combinator. It signals to Check Syntax
               that this is where a contract begins.</div></p><p>The first element in the
               vector should be a unique (in the sense of <span class="RktSym"><a href="Equality.html#%28def._%28%28quote._~23~25kernel%29._eq~3f%29%29" class="RktValLink" data-pltdoc="x">eq?</a></span>) value
               that Check Syntax can use a tag to match up this contract with
               its subpieces (specified by the two following syntax properties).</p><p>The second and third elements of the vector are syntax objects
               from pieces of the contract, and Check Syntax will color them.
               The first list should contain subparts that are the responsibility
               of parties (typically modules) that provide implementations of the contract.
               The second list should contain subparts that are the
               responsibility of clients.</p><p>For example, in <span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%2A%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span>*</a></span><span class="stt"> </span><span class="RktPn">(</span><span class="RktPn">)</span><span class="stt"> </span><span class="RktPn">#:pre</span><span class="stt"> </span><span class="RktVal">#t</span><span class="stt"> </span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="stt"> </span><span class="RktPn">#:post</span><span class="stt"> </span><span class="RktVal">#t</span><span class="RktPn">)</span>,
               the <span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%2A%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span>*</a></span> and the <span class="RktPn">#:post</span> should be in the first
               list and <span class="RktPn">#:pre</span> in the second list.</p></li><li><p><div class="SIntrapara"><a name="(idx._(gentag._188._(lib._scribblings/reference/reference..scrbl)))"></a>
</div><div class="SIntrapara"><span class="RktVal">'</span><span class="RktVal">racket/contract:negative-position</span><span class="hspace">&nbsp;</span><span class="RktSym">:</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></div><div class="SIntrapara">This property should be attached to sub-expressions of
 a contract combinator that are expected to be other contracts.
 The value of the property should be the key (the first element from
 the vector for the <span class="RktVal">'</span><span class="RktVal">racket/contract:contract</span> property)
 indicating which contract this is.</div></p><p>This property should be used when the expression&rsquo;s value is a contract
 that clients are responsible for. </p></li><li><p><div class="SIntrapara"><a name="(idx._(gentag._189._(lib._scribblings/reference/reference..scrbl)))"></a>
</div><div class="SIntrapara"><span class="RktVal">'</span><span class="RktVal">racket/contract:positive-position</span><span class="hspace">&nbsp;</span><span class="RktSym">:</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></div><div class="SIntrapara">This form is just like <span class="RktVal">'</span><span class="RktVal">racket/contract:negative-position</span>,
 except that it should be used when the expression&rsquo;s value is
 a contract that the original party should be responsible for.</div></p></li><li><p><div class="SIntrapara"><a name="(idx._(gentag._190._(lib._scribblings/reference/reference..scrbl)))"></a>
</div><div class="SIntrapara"><span class="RktVal">'</span><span class="RktVal">racket/contract:contract-on-boundary</span><span class="hspace">&nbsp;</span><span class="RktSym">:</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></div><div class="SIntrapara">The presence of this property tells Check Syntax that it
 should start coloring from this point. It expects the expression
 to be a contract
 (and, thus, to have the <span class="RktVal">'</span><span class="RktVal">racket/contract:contract</span> property);
 this property indicates that this contract is on a (module) boundary.</div></p><p>(The value of the property is not used.)</p></li><li><p><div class="SIntrapara"><a name="(idx._(gentag._191._(lib._scribblings/reference/reference..scrbl)))"></a>
</div><div class="SIntrapara"><span class="RktVal">'</span><span class="RktVal">racket/contract:internal-contract</span><span class="hspace">&nbsp;</span><span class="RktSym">:</span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></div><div class="SIntrapara">Like <span class="RktVal">'</span><span class="RktVal">racket/contract:contract-on-boundary</span>, the presence
 of this property triggers coloring, but this is meant for use
 when the party (module) containing the contract (regardless of whether
 or not this module exports anything matching the contract)
 can be blamed for violating the contract. This comes into play
 for <span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3ei%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span>i</a></span> contracts, since the contract itself has
 access to values under contract via the dependency.</div></p></li></ul><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>syntax</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(form._((lib._racket/contract/private/guts..rkt)._define/final-prop))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._define%2Ffinal-prop%29%29" class="RktStxDef RktStxLink" data-pltdoc="x">define/final-prop</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">header</span><span class="hspace">&nbsp;</span><span class="RktVar">body</span><span class="hspace">&nbsp;</span><span class="RktMeta">...</span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="stt">&nbsp;</span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="specgrammar"><tr><td align="right" valign="baseline"><span class="RktVar">header</span></td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="center" valign="baseline">=</td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="left" valign="baseline"><span class="RktVar">main-id</span></td></tr><tr><td align="right" valign="baseline"><span class="stt">&nbsp;</span></td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="center" valign="baseline">|</td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="left" valign="baseline"><span class="RktPn">(</span><span class="RktVar">main-id</span><span class="hspace">&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span><span class="RktMeta">...</span><span class="RktPn">)</span></td></tr><tr><td align="right" valign="baseline"><span class="stt">&nbsp;</span></td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="center" valign="baseline">|</td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="left" valign="baseline"><span class="RktPn">(</span><span class="RktVar">main-id</span><span class="hspace">&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span><span class="RktMeta">...</span><span class="hspace">&nbsp;</span><span class="RktPn">. </span><span class="RktVar">id</span><span class="RktPn">)</span></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">The same as <span class="RktPn">(</span><span class="RktSym"><a href="define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define%29%29" class="RktStxLink" data-pltdoc="x">define</a></span><span class="stt"> </span><span class="RktVar">header</span><span class="stt"> </span><span class="RktVar">body</span><span class="stt"> </span><span class="RktMeta"><a href="stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29._......%29%29" class="RktStxLink" data-pltdoc="x">...</a></span><span class="RktPn">)</span>, except that uses of
            <span class="RktVar">main-id</span> in the header are annotated
            with the <span class="RktVal">'</span><span class="RktVal">racket/contract:contract</span> property
            (as above).</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>syntax</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(form._((lib._racket/contract/private/guts..rkt)._define/subexpression-pos-prop))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28form._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._define%2Fsubexpression-pos-prop%29%29" class="RktStxDef RktStxLink" data-pltdoc="x">define/subexpression-pos-prop</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">header</span><span class="hspace">&nbsp;</span><span class="RktVar">body</span><span class="hspace">&nbsp;</span><span class="RktMeta">...</span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="stt">&nbsp;</span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="specgrammar"><tr><td align="right" valign="baseline"><span class="RktVar">header</span></td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="center" valign="baseline">=</td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="left" valign="baseline"><span class="RktVar">main-id</span></td></tr><tr><td align="right" valign="baseline"><span class="stt">&nbsp;</span></td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="center" valign="baseline">|</td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="left" valign="baseline"><span class="RktPn">(</span><span class="RktVar">main-id</span><span class="hspace">&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span><span class="RktMeta">...</span><span class="RktPn">)</span></td></tr><tr><td align="right" valign="baseline"><span class="stt">&nbsp;</span></td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="center" valign="baseline">|</td><td align="left" valign="baseline"><span class="stt">&nbsp;</span></td><td align="left" valign="baseline"><span class="RktPn">(</span><span class="RktVar">main-id</span><span class="hspace">&nbsp;</span><span class="RktVar">id</span><span class="hspace">&nbsp;</span><span class="RktMeta">...</span><span class="hspace">&nbsp;</span><span class="RktPn">. </span><span class="RktVar">id</span><span class="RktPn">)</span></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">The same as <span class="RktPn">(</span><span class="RktSym"><a href="define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define%29%29" class="RktStxLink" data-pltdoc="x">define</a></span><span class="stt"> </span><span class="RktVar">header</span><span class="stt"> </span><span class="RktVar">body</span><span class="stt"> </span><span class="RktMeta"><a href="stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29._......%29%29" class="RktStxLink" data-pltdoc="x">...</a></span><span class="RktPn">)</span>, except that uses of
            <span class="RktVar">main-id</span> in the header are annotated
            with the <span class="RktVal">'</span><span class="RktVal">racket/contract:contract</span> property
            (as above) and arguments are annotated with the
            <span class="RktVal">'</span><span class="RktVal">racket/contract:positive-position</span> property.</div></p><h5 x-source-module="(lib &quot;scribblings/reference/reference.scrbl&quot;)" x-source-pkg="racket-doc" x-part-tag="&quot;Utilities_for_Building_New_Combinators&quot;">8.7.4<tt>&nbsp;</tt><a name="(part._.Utilities_for_.Building_.New_.Combinators)"></a>Utilities for Building New Combinators</h5><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._contract-stronger~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-stronger~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">contract-stronger?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">c1</span><span class="hspace">&nbsp;</span><span class="RktVar">c2</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">c1</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">c2</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Returns <span class="RktVal">#t</span> if the contract <span class="RktVar">c1</span> accepts either fewer
  or the same set of values that <span class="RktVar">c2</span> does.</div></p><p><a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">Chaperone contracts</span></a> and <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a> that are the same
  (i.e., where <span class="RktVar">c1</span> is <span class="RktSym"><a href="Equality.html#%28def._%28%28quote._~23~25kernel%29._equal~3f%29%29" class="RktValLink" data-pltdoc="x">equal?</a></span> to <span class="RktVar">c2</span>) are
  considered to always be stronger than each other.</p><p>This function is conservative, so it may return <span class="RktVal">#f</span> when
  <span class="RktVar">c1</span> does, in fact, accept fewer values.</p><p><div class="SIntrapara">Examples:</div><div class="SIntrapara"><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-stronger~3f%29%29" class="RktValLink" data-pltdoc="x">contract-stronger?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#t</span></p></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-stronger~3f%29%29" class="RktValLink" data-pltdoc="x">contract-stronger?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._between%2Fc%29%29" class="RktValLink" data-pltdoc="x">between/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">25</span><span class="hspace">&nbsp;</span><span class="RktVal">75</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._between%2Fc%29%29" class="RktValLink" data-pltdoc="x">between/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">0</span><span class="hspace">&nbsp;</span><span class="RktVal">100</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#t</span></p></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-stronger~3f%29%29" class="RktValLink" data-pltdoc="x">contract-stronger?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._between%2Fc%29%29" class="RktValLink" data-pltdoc="x">between/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">0</span><span class="hspace">&nbsp;</span><span class="RktVal">100</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._between%2Fc%29%29" class="RktValLink" data-pltdoc="x">between/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">25</span><span class="hspace">&nbsp;</span><span class="RktVal">75</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#f</span></p></td></tr><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-stronger~3f%29%29" class="RktValLink" data-pltdoc="x">contract-stronger?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._between%2Fc%29%29" class="RktValLink" data-pltdoc="x">between/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal"><span class="nobreak">-1</span>0</span><span class="hspace">&nbsp;</span><span class="RktVal">0</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._between%2Fc%29%29" class="RktValLink" data-pltdoc="x">between/c</a></span><span class="hspace">&nbsp;</span><span class="RktVal">0</span><span class="hspace">&nbsp;</span><span class="RktVal">10</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#f</span></p></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-stronger~3f%29%29" class="RktValLink" data-pltdoc="x">contract-stronger?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._and%29%29" class="RktStxLink" data-pltdoc="x">and</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._real~3f%29%29" class="RktValLink" data-pltdoc="x">real?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="generic-numbers.html#%28def._%28%28quote._~23~25kernel%29._~3c~3d%29%29" class="RktValLink" data-pltdoc="x">&lt;=</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="hspace">&nbsp;</span><span class="RktVal">0</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._and%29%29" class="RktStxLink" data-pltdoc="x">and</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._real~3f%29%29" class="RktValLink" data-pltdoc="x">real?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="generic-numbers.html#%28def._%28%28quote._~23~25kernel%29._~3c~3d%29%29" class="RktValLink" data-pltdoc="x">&lt;=</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="hspace">&nbsp;</span><span class="RktVal">100</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><p><span class="RktRes">#f</span></p></td></tr></table></blockquote></div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._contract-equivalent~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-equivalent~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">contract-equivalent?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">c1</span><span class="hspace">&nbsp;</span><span class="RktVar">c2</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">c1</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">c2</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Returns <span class="RktVal">#t</span> if the contract <span class="RktVar">c1</span> accepts the same
  set of values that <span class="RktVar">c2</span> does.</div></p><p><a href="contracts.html#%28tech._chaperone._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">Chaperone contracts</span></a> and <a href="contracts.html#%28tech._flat._contract%29" class="techoutside" data-pltdoc="x"><span class="techinside">flat contracts</span></a> that are the same
  (i.e., where <span class="RktVar">c1</span> is <span class="RktSym"><a href="Equality.html#%28def._%28%28quote._~23~25kernel%29._equal~3f%29%29" class="RktValLink" data-pltdoc="x">equal?</a></span> to <span class="RktVar">c2</span>) are
  considered to always be equivalent to each other.</p><p>This function is conservative, so it may return <span class="RktVal">#f</span> when
  <span class="RktVar">c1</span> does, in fact, accept the same set of values that <span class="RktVar">c2</span> does.</p><p><div class="SIntrapara">Examples:</div><div class="SIntrapara"><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-equivalent~3f%29%29" class="RktValLink" data-pltdoc="x">contract-equivalent?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#t</span></p></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-equivalent~3f%29%29" class="RktValLink" data-pltdoc="x">contract-equivalent?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._non-empty-listof%29%29" class="RktValLink" data-pltdoc="x">non-empty-listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._cons%2Fc%29%29" class="RktValLink" data-pltdoc="x">cons/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._integer~3f%29%29" class="RktValLink" data-pltdoc="x">integer?</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><p><span class="RktRes">#t</span></p></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">&gt; </span><span class="RktPn">(</span><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-equivalent~3f%29%29" class="RktValLink" data-pltdoc="x">contract-equivalent?</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._and%29%29" class="RktStxLink" data-pltdoc="x">and</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._real~3f%29%29" class="RktValLink" data-pltdoc="x">real?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._and%29%29" class="RktStxLink" data-pltdoc="x">and</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._number~3f%29%29" class="RktValLink" data-pltdoc="x">number?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="generic-numbers.html#%28def._%28%28quote._~23~25kernel%29._~3e~3d%29%29" class="RktValLink" data-pltdoc="x">&gt;=</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="generic-numbers.html#%28def._%28%28lib._racket%2Fmath..rkt%29._sqr%29%29" class="RktValLink" data-pltdoc="x">sqr</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktVal">0</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="hspace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="lambda.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~ce~bb%29%29" class="RktStxLink" data-pltdoc="x">&#955;</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._and%29%29" class="RktStxLink" data-pltdoc="x">and</a></span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._real~3f%29%29" class="RktValLink" data-pltdoc="x">real?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._real~3f%29%29" class="RktValLink" data-pltdoc="x">real?</a></span><span class="hspace">&nbsp;</span><span class="RktSym">x</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><p><span class="RktRes">#f</span></p></td></tr></table></blockquote></div></p><p class="SHistory">Added in version 6.90.0.30 of package <span class="stt">base</span>.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._contract-first-order-passes~3f))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-first-order-passes~3f%29%29" class="RktValDef RktValLink" data-pltdoc="x">contract-first-order-passes?</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">contract</span><span class="hspace">&nbsp;</span><span class="RktVar">v</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">contract</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">v</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Returns a boolean indicating whether the first-order tests
of <span class="RktVar">contract</span> pass for <span class="RktVar">v</span>.</div></p><p>If it returns <span class="RktVal">#f</span>, the contract is guaranteed not to
hold for that value; if it returns <span class="RktVal">#t</span>, the contract
may or may not hold. If the contract is a first-order
contract, a result of <span class="RktVal">#t</span> guarantees that the
contract holds.</p><p>See also <span class="RktSym">contract-first-order-okay-to-give-up?</span> and
<span class="RktSym">contract-first-order-try-less-hard</span>.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._racket/contract/private/guts..rkt)._contract-first-order))"></a><span title="Provided from: racket/contract/combinator, racket/contract, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract-first-order%29%29" class="RktValDef RktValLink" data-pltdoc="x">contract-first-order</a></span></span><span class="hspace">&nbsp;</span><span class="RktVar">c</span><span class="RktPn">)</span><span class="hspace">&nbsp;</span>&rarr;<span class="hspace">&nbsp;</span><span class="RktPn">(</span><span class="RktSym"><a href="function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3e%29%29" class="RktStxLink" data-pltdoc="x"><span class="nobreak">-&gt;</span></a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fmisc..rkt%29._any%2Fc%29%29" class="RktValLink" data-pltdoc="x">any/c</a></span><span class="hspace">&nbsp;</span><span class="RktSym"><a href="booleans.html#%28def._%28%28quote._~23~25kernel%29._boolean~3f%29%29" class="RktValLink" data-pltdoc="x">boolean?</a></span><span class="RktPn">)</span></p></blockquote></td></tr><tr><td><span class="hspace">&nbsp;&nbsp;</span><span class="RktVar">c</span><span class="hspace">&nbsp;</span>:<span class="hspace">&nbsp;</span><span class="RktSym"><a href="contract-utilities.html#%28def._%28%28lib._racket%2Fcontract%2Fprivate%2Fguts..rkt%29._contract~3f%29%29" class="RktValLink" data-pltdoc="x">contract?</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Produces the first-order test used by <span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span> to match values to
higher-order contracts.</div></p><div class="navsetbottom"><span class="navleft"><form class="searchform"><input class="searchbox" style="color: #888;" type="text" tabindex="1" value="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, &quot;7.7&quot;, &quot;../&quot;);" onfocus="this.style.color=&quot;black&quot;; this.style.textAlign=&quot;left&quot;; if (this.value == &quot;...search manuals...&quot;) this.value=&quot;&quot;;" onblur="if (this.value.match(/^ *$/)) { this.style.color=&quot;#888&quot;; this.style.textAlign=&quot;center&quot;; this.value=&quot;...search manuals...&quot;; }"/></form>&nbsp;&nbsp;<a href="../index.html" title="up to the documentation top" data-pltdoc="x" onclick="return GotoPLTRoot(&quot;7.7&quot;);">top</a></span><span class="navright">&nbsp;&nbsp;<a href="attaching-contracts-to-values.html" title="backward to &quot;8.6 Attaching Contracts to Values&quot;" data-pltdoc="x">&larr; prev</a>&nbsp;&nbsp;<a href="contracts.html" title="up to &quot;8 Contracts&quot;" data-pltdoc="x">up</a>&nbsp;&nbsp;<a href="contract-utilities.html" title="forward to &quot;8.8 Contract Utilities&quot;" data-pltdoc="x">next &rarr;</a></span>&nbsp;</div></div></div><div id="contextindicator">&nbsp;</div></body></html>